diff --git a/declarations/plugins/WatchIgnorePlugin.d.ts b/declarations/plugins/WatchIgnorePlugin.d.ts
index 34271d801..5b11c3cfe 100644
--- a/declarations/plugins/WatchIgnorePlugin.d.ts
+++ b/declarations/plugins/WatchIgnorePlugin.d.ts
@@ -4,10 +4,9 @@
  * Run `yarn special-lint-fix` to update
  */
 
-/**
- * A list of RegExps or absolute paths to directories or files that should be ignored
- */
-export type WatchIgnorePluginOptions = [
-	(string | RegExp),
-	...(string | RegExp)[]
-];
+export interface WatchIgnorePluginOptions {
+	/**
+	 * A list of RegExps or absolute paths to directories or files that should be ignored
+	 */
+	paths: [(string | RegExp), ...(string | RegExp)[]];
+}
diff --git a/declarations/plugins/debug/ProfilingPlugin.d.ts b/declarations/plugins/debug/ProfilingPlugin.d.ts
index d3cd664ad..5e1404f57 100644
--- a/declarations/plugins/debug/ProfilingPlugin.d.ts
+++ b/declarations/plugins/debug/ProfilingPlugin.d.ts
@@ -6,7 +6,7 @@
 
 export interface ProfilingPluginOptions {
 	/**
-	 * Path to the output file e.g. `profiling/events.json`. Defaults to `events.json`.
+	 * Path to the output file e.g. `path.resolve(__dirname, 'profiling/events.json')`. Defaults to `events.json`.
 	 */
 	outputPath?: string;
 }
diff --git a/examples/dll-app-and-vendor/1-app/webpack.config.js b/examples/dll-app-and-vendor/1-app/webpack.config.js
index 2f43dacef..1f3343592 100644
--- a/examples/dll-app-and-vendor/1-app/webpack.config.js
+++ b/examples/dll-app-and-vendor/1-app/webpack.config.js
@@ -11,7 +11,6 @@ module.exports = {
 	},
 	plugins: [
 		new webpack.DllReferencePlugin({
-			context: ".",
 			manifest: require("../0-vendor/dist/vendor-manifest.json") // eslint-disable-line
 		})
 	]
diff --git a/lib/BannerPlugin.js b/lib/BannerPlugin.js
index dd48a2106..8bdb21e5c 100644
--- a/lib/BannerPlugin.js
+++ b/lib/BannerPlugin.js
@@ -31,7 +31,10 @@ class BannerPlugin {
 	 * @param {BannerPluginArgument} options options object
 	 */
 	constructor(options) {
-		validateOptions(schema, options, "Banner Plugin");
+		validateOptions(schema, options, {
+			name: "Banner Plugin",
+			baseDataPath: "options"
+		});
 
 		if (typeof options === "string" || typeof options === "function") {
 			options = {
diff --git a/lib/DllPlugin.js b/lib/DllPlugin.js
index 15f68b976..3795af124 100644
--- a/lib/DllPlugin.js
+++ b/lib/DllPlugin.js
@@ -19,7 +19,10 @@ class DllPlugin {
 	 * @param {DllPluginOptions} options options object
 	 */
 	constructor(options) {
-		validateOptions(schema, options, "Dll Plugin");
+		validateOptions(schema, options, {
+			name: "Dll Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 	}
 
diff --git a/lib/DllReferencePlugin.js b/lib/DllReferencePlugin.js
index 71bdbbbcc..89aa9645e 100644
--- a/lib/DllReferencePlugin.js
+++ b/lib/DllReferencePlugin.js
@@ -23,7 +23,10 @@ class DllReferencePlugin {
 	 * @param {DllReferencePluginOptions} options options object
 	 */
 	constructor(options) {
-		validateOptions(schema, options, "Dll Reference Plugin");
+		validateOptions(schema, options, {
+			name: "Dll Reference Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 		/** @type {WeakMap<Object, {path: string, data: DllReferencePluginOptionsManifest?, error: Error?}>} */
 		this._compilationData = new WeakMap();
diff --git a/lib/IgnorePlugin.js b/lib/IgnorePlugin.js
index a77eb2e2c..943bead9e 100644
--- a/lib/IgnorePlugin.js
+++ b/lib/IgnorePlugin.js
@@ -17,7 +17,10 @@ class IgnorePlugin {
 	 * @param {IgnorePluginOptions} options IgnorePlugin options
 	 */
 	constructor(options) {
-		validateOptions(schema, options, "IgnorePlugin");
+		validateOptions(schema, options, {
+			name: "Ignore Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 
 		/** @private @type {Function} */
diff --git a/lib/LoaderOptionsPlugin.js b/lib/LoaderOptionsPlugin.js
index d88fa68af..da9126c0d 100644
--- a/lib/LoaderOptionsPlugin.js
+++ b/lib/LoaderOptionsPlugin.js
@@ -18,9 +18,11 @@ class LoaderOptionsPlugin {
 	/**
 	 * @param {LoaderOptionsPluginOptions} options options object
 	 */
-	constructor(options) {
-		validateOptions(schema, options || {}, "Loader Options Plugin");
-
+	constructor(options = {}) {
+		validateOptions(schema, options, {
+			name: "Loader Options Plugin",
+			baseDataPath: "options"
+		});
 		if (typeof options !== "object") options = {};
 		if (!options.test) {
 			options.test = {
diff --git a/lib/ProgressPlugin.js b/lib/ProgressPlugin.js
index ff08a8138..44565d2ad 100644
--- a/lib/ProgressPlugin.js
+++ b/lib/ProgressPlugin.js
@@ -81,7 +81,10 @@ class ProgressPlugin {
 		}
 
 		options = options || {};
-		validateOptions(schema, options, "Progress Plugin");
+		validateOptions(schema, options || {}, {
+			name: "Progress Plugin",
+			baseDataPath: "options"
+		});
 		options = { ...ProgressPlugin.defaultOptions, ...options };
 
 		this.profile = options.profile;
diff --git a/lib/SourceMapDevToolPlugin.js b/lib/SourceMapDevToolPlugin.js
index d0105f6a5..24ad4d45c 100644
--- a/lib/SourceMapDevToolPlugin.js
+++ b/lib/SourceMapDevToolPlugin.js
@@ -82,7 +82,10 @@ class SourceMapDevToolPlugin {
 	 * @throws {Error} throws error, if got more than 1 arguments
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options, "SourceMap DevTool Plugin");
+		validateOptions(schema, options || {}, {
+			name: "SourceMap DevTool Plugin",
+			baseDataPath: "options"
+		});
 
 		/** @type {string | false} */
 		this.sourceMapFilename = options.filename;
diff --git a/lib/WatchIgnorePlugin.js b/lib/WatchIgnorePlugin.js
index e6f255085..f248652b9 100644
--- a/lib/WatchIgnorePlugin.js
+++ b/lib/WatchIgnorePlugin.js
@@ -72,11 +72,14 @@ class IgnoringWatchFileSystem {
 
 class WatchIgnorePlugin {
 	/**
-	 * @param {WatchIgnorePluginOptions} paths list of paths
+	 * @param {WatchIgnorePluginOptions} options options
 	 */
-	constructor(paths) {
-		validateOptions(schema, paths, "Watch Ignore Plugin");
-		this.paths = paths;
+	constructor(options) {
+		validateOptions(schema, options, {
+			name: "Watch Ignore Plugin",
+			baseDataPath: "options"
+		});
+		this.paths = options.paths;
 	}
 
 	/**
diff --git a/lib/WebpackOptionsValidationError.js b/lib/WebpackOptionsValidationError.js
deleted file mode 100644
index e6806b208..000000000
--- a/lib/WebpackOptionsValidationError.js
+++ /dev/null
@@ -1,381 +0,0 @@
-/*
-	MIT License http://www.opensource.org/licenses/mit-license.php
-	Author Gajus Kuizinas @gajus
-*/
-
-"use strict";
-
-const webpackOptionsSchema = require("../schemas/WebpackOptions.json");
-const WebpackError = require("./WebpackError");
-
-const getSchemaPart = (path, parents, additionalPath) => {
-	parents = parents || 0;
-	path = path.split("/", path.length - parents);
-	if (additionalPath) {
-		additionalPath = additionalPath.split("/");
-		path = path.concat(additionalPath);
-	}
-	let schemaPart = webpackOptionsSchema;
-	for (let i = 1; i < path.length; i++) {
-		const inner = schemaPart[path[i]];
-		if (inner) schemaPart = inner;
-	}
-	return schemaPart;
-};
-
-const getSchemaPartText = (schemaPart, additionalPath) => {
-	if (additionalPath) {
-		for (let i = 0; i < additionalPath.length; i++) {
-			const inner = schemaPart[additionalPath[i]];
-			if (inner) schemaPart = inner;
-		}
-	}
-	while (schemaPart.$ref) {
-		schemaPart = getSchemaPart(schemaPart.$ref);
-	}
-	let schemaText = WebpackOptionsValidationError.formatSchema(schemaPart);
-	if (schemaPart.description) {
-		schemaText += `\n-> ${schemaPart.description}`;
-	}
-	return schemaText;
-};
-
-const getSchemaPartDescription = schemaPart => {
-	while (schemaPart.$ref) {
-		schemaPart = getSchemaPart(schemaPart.$ref);
-	}
-	if (schemaPart.description) {
-		return `\n-> ${schemaPart.description}`;
-	}
-	return "";
-};
-
-const SPECIFICITY = {
-	type: 1,
-	oneOf: 1,
-	anyOf: 1,
-	allOf: 1,
-	additionalProperties: 2,
-	enum: 1,
-	instanceof: 1,
-	required: 2,
-	minimum: 2,
-	uniqueItems: 2,
-	minLength: 2,
-	minItems: 2,
-	minProperties: 2,
-	absolutePath: 2
-};
-
-const filterMax = (array, fn) => {
-	const max = array.reduce((max, item) => Math.max(max, fn(item)), 0);
-	return array.filter(item => fn(item) === max);
-};
-
-const filterChildren = children => {
-	children = filterMax(children, err =>
-		err.dataPath ? err.dataPath.length : 0
-	);
-	children = filterMax(children, err => SPECIFICITY[err.keyword] || 2);
-	return children;
-};
-
-const indent = (str, prefix, firstLine) => {
-	if (firstLine) {
-		return prefix + str.replace(/\n(?!$)/g, "\n" + prefix);
-	} else {
-		return str.replace(/\n(?!$)/g, `\n${prefix}`);
-	}
-};
-
-class WebpackOptionsValidationError extends WebpackError {
-	constructor(validationErrors) {
-		super(
-			"Invalid configuration object. " +
-				"Webpack has been initialised using a configuration object that does not match the API schema.\n" +
-				validationErrors
-					.map(
-						err =>
-							" - " +
-							indent(
-								WebpackOptionsValidationError.formatValidationError(err),
-								"   ",
-								false
-							)
-					)
-					.join("\n")
-		);
-
-		this.name = "WebpackOptionsValidationError";
-		this.validationErrors = validationErrors;
-
-		Error.captureStackTrace(this, this.constructor);
-	}
-
-	static formatSchema(schema, prevSchemas) {
-		prevSchemas = prevSchemas || [];
-
-		const formatInnerSchema = (innerSchema, addSelf) => {
-			if (!addSelf) {
-				return WebpackOptionsValidationError.formatSchema(
-					innerSchema,
-					prevSchemas
-				);
-			}
-			if (prevSchemas.includes(innerSchema)) {
-				return "(recursive)";
-			}
-			return WebpackOptionsValidationError.formatSchema(
-				innerSchema,
-				prevSchemas.concat(schema)
-			);
-		};
-
-		if (schema.type === "string") {
-			if (schema.minLength === 1) {
-				return "non-empty string";
-			}
-			if (schema.minLength > 1) {
-				return `string (min length ${schema.minLength})`;
-			}
-			return "string";
-		}
-		if (schema.type === "boolean") {
-			return "boolean";
-		}
-		if (schema.type === "number") {
-			return "number";
-		}
-		if (schema.type === "object") {
-			if (schema.properties) {
-				const required = schema.required || [];
-				return `object { ${Object.keys(schema.properties)
-					.map(property => {
-						if (!required.includes(property)) return property + "?";
-						return property;
-					})
-					.concat(schema.additionalProperties ? ["…"] : [])
-					.join(", ")} }`;
-			}
-			if (schema.additionalProperties) {
-				return `object { <key>: ${formatInnerSchema(
-					schema.additionalProperties
-				)} }`;
-			}
-			return "object";
-		}
-		if (schema.type === "array") {
-			return `[${formatInnerSchema(schema.items)}]`;
-		}
-
-		switch (schema.instanceof) {
-			case "Function":
-				return "function";
-			case "RegExp":
-				return "RegExp";
-		}
-
-		if (schema.enum) {
-			return schema.enum.map(item => JSON.stringify(item)).join(" | ");
-		}
-
-		if (schema.$ref) {
-			return formatInnerSchema(getSchemaPart(schema.$ref), true);
-		}
-		if (schema.allOf) {
-			return schema.allOf.map(formatInnerSchema).join(" & ");
-		}
-		if (schema.oneOf) {
-			return schema.oneOf.map(formatInnerSchema).join(" | ");
-		}
-		if (schema.anyOf) {
-			return schema.anyOf.map(formatInnerSchema).join(" | ");
-		}
-		return JSON.stringify(schema, null, 2);
-	}
-
-	static formatValidationError(err) {
-		const dataPath = `configuration${err.dataPath}`;
-		if (err.keyword === "additionalProperties") {
-			const baseMessage = `${dataPath} has an unknown property '${
-				err.params.additionalProperty
-			}'. These properties are valid:\n${getSchemaPartText(err.parentSchema)}`;
-			if (!err.dataPath) {
-				switch (err.params.additionalProperty) {
-					case "debug":
-						return (
-							`${baseMessage}\n` +
-							"The 'debug' property was removed in webpack 2.0.0.\n" +
-							"Loaders should be updated to allow passing this option via loader options in module.rules.\n" +
-							"Until loaders are updated one can use the LoaderOptionsPlugin to switch loaders into debug mode:\n" +
-							"plugins: [\n" +
-							"  new webpack.LoaderOptionsPlugin({\n" +
-							"    debug: true\n" +
-							"  })\n" +
-							"]"
-						);
-				}
-				return (
-					`${baseMessage}\n` +
-					"For typos: please correct them.\n" +
-					"For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.\n" +
-					"  Loaders should be updated to allow passing options via loader options in module.rules.\n" +
-					"  Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:\n" +
-					"  plugins: [\n" +
-					"    new webpack.LoaderOptionsPlugin({\n" +
-					"      // test: /\\.xxx$/, // may apply this only for some modules\n" +
-					"      options: {\n" +
-					`        ${err.params.additionalProperty}: …\n` +
-					"      }\n" +
-					"    })\n" +
-					"  ]"
-				);
-			}
-			return baseMessage;
-		} else if (err.keyword === "oneOf" || err.keyword === "anyOf") {
-			if (err.children && err.children.length > 0) {
-				if (err.schema.length === 1) {
-					const lastChild = err.children[err.children.length - 1];
-					const remainingChildren = err.children.slice(
-						0,
-						err.children.length - 1
-					);
-					return WebpackOptionsValidationError.formatValidationError({
-						...lastChild,
-						children: remainingChildren,
-						parentSchema: { ...err.parentSchema, ...lastChild.parentSchema }
-					});
-				}
-				const children = filterChildren(err.children);
-				if (children.length === 1) {
-					return WebpackOptionsValidationError.formatValidationError(
-						children[0]
-					);
-				}
-				return (
-					`${dataPath} should be one of these:\n${getSchemaPartText(
-						err.parentSchema
-					)}\n` +
-					`Details:\n${children
-						.map(
-							err =>
-								" * " +
-								indent(
-									WebpackOptionsValidationError.formatValidationError(err),
-									"   ",
-									false
-								)
-						)
-						.join("\n")}`
-				);
-			}
-			return `${dataPath} should be one of these:\n${getSchemaPartText(
-				err.parentSchema
-			)}`;
-		} else if (err.keyword === "enum") {
-			if (
-				err.parentSchema &&
-				err.parentSchema.enum &&
-				err.parentSchema.enum.length === 1
-			) {
-				return `${dataPath} should be ${getSchemaPartText(err.parentSchema)}`;
-			}
-			return `${dataPath} should be one of these:\n${getSchemaPartText(
-				err.parentSchema
-			)}`;
-		} else if (err.keyword === "allOf") {
-			return `${dataPath} should be:\n${getSchemaPartText(err.parentSchema)}`;
-		} else if (err.keyword === "type") {
-			switch (err.params.type) {
-				case "object":
-					return `${dataPath} should be an object.${getSchemaPartDescription(
-						err.parentSchema
-					)}`;
-				case "string":
-					return `${dataPath} should be a string.${getSchemaPartDescription(
-						err.parentSchema
-					)}`;
-				case "boolean":
-					return `${dataPath} should be a boolean.${getSchemaPartDescription(
-						err.parentSchema
-					)}`;
-				case "number":
-					return `${dataPath} should be a number.${getSchemaPartDescription(
-						err.parentSchema
-					)}`;
-				case "array":
-					return `${dataPath} should be an array:\n${getSchemaPartText(
-						err.parentSchema
-					)}`;
-			}
-			return `${dataPath} should be ${err.params.type}:\n${getSchemaPartText(
-				err.parentSchema
-			)}`;
-		} else if (err.keyword === "instanceof") {
-			return `${dataPath} should be an instance of ${getSchemaPartText(
-				err.parentSchema
-			)}`;
-		} else if (err.keyword === "required") {
-			const missingProperty = err.params.missingProperty.replace(/^\./, "");
-			return `${dataPath} misses the property '${missingProperty}'.\n${getSchemaPartText(
-				err.parentSchema,
-				["properties", missingProperty]
-			)}`;
-		} else if (err.keyword === "minimum") {
-			return `${dataPath} ${err.message}.${getSchemaPartDescription(
-				err.parentSchema
-			)}`;
-		} else if (err.keyword === "uniqueItems") {
-			return `${dataPath} should not contain the item '${
-				err.data[err.params.i]
-			}' twice.${getSchemaPartDescription(err.parentSchema)}`;
-		} else if (
-			err.keyword === "minLength" ||
-			err.keyword === "minItems" ||
-			err.keyword === "minProperties"
-		) {
-			if (err.params.limit === 1) {
-				switch (err.keyword) {
-					case "minLength":
-						return `${dataPath} should be an non-empty string.${getSchemaPartDescription(
-							err.parentSchema
-						)}`;
-					case "minItems":
-						return `${dataPath} should be an non-empty array.${getSchemaPartDescription(
-							err.parentSchema
-						)}`;
-					case "minProperties":
-						return `${dataPath} should be an non-empty object.${getSchemaPartDescription(
-							err.parentSchema
-						)}`;
-				}
-				return `${dataPath} should be not empty.${getSchemaPartDescription(
-					err.parentSchema
-				)}`;
-			} else {
-				return `${dataPath} ${err.message}${getSchemaPartDescription(
-					err.parentSchema
-				)}`;
-			}
-		} else if (err.keyword === "absolutePath") {
-			const baseMessage = `${dataPath}: ${
-				err.message
-			}${getSchemaPartDescription(err.parentSchema)}`;
-			if (dataPath === "configuration.output.filename") {
-				return (
-					`${baseMessage}\n` +
-					"Please use output.path to specify absolute path and output.filename for the file name."
-				);
-			}
-			return baseMessage;
-		} else {
-			return `${dataPath} ${err.message} (${JSON.stringify(
-				err,
-				null,
-				2
-			)}).\n${getSchemaPartText(err.parentSchema)}`;
-		}
-	}
-}
-
-module.exports = WebpackOptionsValidationError;
diff --git a/lib/debug/ProfilingPlugin.js b/lib/debug/ProfilingPlugin.js
index 575405a09..e2912c92f 100644
--- a/lib/debug/ProfilingPlugin.js
+++ b/lib/debug/ProfilingPlugin.js
@@ -161,12 +161,14 @@ const pluginName = "ProfilingPlugin";
 
 class ProfilingPlugin {
 	/**
-	 * @param {ProfilingPluginOptions=} opts options object
+	 * @param {ProfilingPluginOptions=} options options object
 	 */
-	constructor(opts) {
-		validateOptions(schema, opts || {}, "Profiling plugin");
-		opts = opts || {};
-		this.outputPath = opts.outputPath || "events.json";
+	constructor(options = {}) {
+		validateOptions(schema, options, {
+			name: "Profiling Plugin",
+			baseDataPath: "options"
+		});
+		this.outputPath = options.outputPath || "events.json";
 	}
 
 	apply(compiler) {
diff --git a/lib/ids/HashedModuleIdsPlugin.js b/lib/ids/HashedModuleIdsPlugin.js
index e39a9d229..f3d087b8d 100644
--- a/lib/ids/HashedModuleIdsPlugin.js
+++ b/lib/ids/HashedModuleIdsPlugin.js
@@ -20,7 +20,10 @@ class HashedModuleIdsPlugin {
 	 * @param {HashedModuleIdsPluginOptions=} options options object
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options || {}, "Hashed Module Ids Plugin");
+		validateOptions(schema, options, {
+			name: "Hashed Module Ids Plugin",
+			baseDataPath: "options"
+		});
 
 		/** @type {HashedModuleIdsPluginOptions} */
 		this.options = {
diff --git a/lib/ids/OccurrenceChunkIdsPlugin.js b/lib/ids/OccurrenceChunkIdsPlugin.js
index 751ce7793..1e58af1ed 100644
--- a/lib/ids/OccurrenceChunkIdsPlugin.js
+++ b/lib/ids/OccurrenceChunkIdsPlugin.js
@@ -20,7 +20,10 @@ class OccurrenceChunkIdsPlugin {
 	 * @param {OccurrenceChunkIdsPluginOptions=} options options object
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options, "Occurrence Order Chunk Ids Plugin");
+		validateOptions(schema, options, {
+			name: "Occurrence Order Chunk Ids Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 	}
 
diff --git a/lib/ids/OccurrenceModuleIdsPlugin.js b/lib/ids/OccurrenceModuleIdsPlugin.js
index 4d594f723..05915b119 100644
--- a/lib/ids/OccurrenceModuleIdsPlugin.js
+++ b/lib/ids/OccurrenceModuleIdsPlugin.js
@@ -22,7 +22,10 @@ class OccurrenceModuleIdsPlugin {
 	 * @param {OccurrenceModuleIdsPluginOptions=} options options object
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options, "Occurrence Order Module Ids Plugin");
+		validateOptions(schema, options, {
+			name: "Occurrence Order Module Ids Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 	}
 
diff --git a/lib/index.js b/lib/index.js
index 453692d66..3e62d02e0 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -5,6 +5,7 @@
 
 "use strict";
 
+const validate = require("schema-utils");
 const util = require("util");
 const { version } = require("../package.json");
 const webpackOptionsSchema = require("../schemas/WebpackOptions.json");
@@ -12,14 +13,13 @@ const Compiler = require("./Compiler");
 const MultiCompiler = require("./MultiCompiler");
 const WebpackOptionsApply = require("./WebpackOptionsApply");
 const WebpackOptionsDefaulter = require("./WebpackOptionsDefaulter");
-const WebpackOptionsValidationError = require("./WebpackOptionsValidationError");
 const validateSchema = require("./validateSchema");
 const webpack = require("./webpack");
 
 module.exports = webpack;
 module.exports.WebpackOptionsApply = WebpackOptionsApply;
 module.exports.WebpackOptionsDefaulter = WebpackOptionsDefaulter;
-module.exports.WebpackOptionsValidationError = WebpackOptionsValidationError;
+module.exports.WebpackOptionsValidationError = validate.ValidationError;
 module.exports.Compiler = Compiler;
 module.exports.MultiCompiler = MultiCompiler;
 module.exports.validate = validateSchema.bind(null, webpackOptionsSchema);
diff --git a/lib/optimize/AggressiveSplittingPlugin.js b/lib/optimize/AggressiveSplittingPlugin.js
index 297f4527b..affc6d993 100644
--- a/lib/optimize/AggressiveSplittingPlugin.js
+++ b/lib/optimize/AggressiveSplittingPlugin.js
@@ -47,7 +47,10 @@ class AggressiveSplittingPlugin {
 	 * @param {AggressiveSplittingPluginOptions=} options options object
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options, "Aggressive Splitting Plugin");
+		validateOptions(schema, options, {
+			name: "Aggressive Splitting Plugin",
+			baseDataPath: "options"
+		});
 
 		this.options = options;
 		if (typeof this.options.minSize !== "number") {
diff --git a/lib/optimize/LimitChunkCountPlugin.js b/lib/optimize/LimitChunkCountPlugin.js
index 47992e737..69f247df4 100644
--- a/lib/optimize/LimitChunkCountPlugin.js
+++ b/lib/optimize/LimitChunkCountPlugin.js
@@ -20,7 +20,10 @@ class LimitChunkCountPlugin {
 	 * @param {LimitChunkCountPluginOptions=} options options object
 	 */
 	constructor(options = {}) {
-		validateOptions(schema, options, "Limit Chunk Count Plugin");
+		validateOptions(schema, options, {
+			name: "Limit Chunk Count Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 	}
 
diff --git a/lib/optimize/MinChunkSizePlugin.js b/lib/optimize/MinChunkSizePlugin.js
index b4bf60fc2..1348fdfd6 100644
--- a/lib/optimize/MinChunkSizePlugin.js
+++ b/lib/optimize/MinChunkSizePlugin.js
@@ -19,7 +19,10 @@ class MinChunkSizePlugin {
 	 * @param {MinChunkSizePluginOptions} options options object
 	 */
 	constructor(options) {
-		validateOptions(schema, options, "Min Chunk Size Plugin");
+		validateOptions(schema, options, {
+			name: "Min Chunk Size Plugin",
+			baseDataPath: "options"
+		});
 		this.options = options;
 	}
 
diff --git a/lib/validateSchema.js b/lib/validateSchema.js
index 0e3af177f..387e4f561 100644
--- a/lib/validateSchema.js
+++ b/lib/validateSchema.js
@@ -1,70 +1,63 @@
 /*
 	MIT License http://www.opensource.org/licenses/mit-license.php
-	Author Gajus Kuizinas @gajus
+	Author Tobias Koppers @sokra
 */
 
 "use strict";
 
-const Ajv = require("ajv");
-const ajv = new Ajv({
-	errorDataPath: "configuration",
-	allErrors: true,
-	verbose: true
-});
-require("ajv-keywords")(ajv, ["instanceof"]);
-require("../schemas/ajv.absolutePath")(ajv);
+const validate = require("schema-utils");
 
 const validateSchema = (schema, options) => {
-	if (Array.isArray(options)) {
-		const errors = Array.from(options).map(options =>
-			validateObject(schema, options)
-		);
-		errors.forEach((list, idx) => {
-			const applyPrefix = err => {
-				err.dataPath = `[${idx}]${err.dataPath}`;
-				if (err.children) {
-					err.children.forEach(applyPrefix);
-				}
-			};
-			list.forEach(applyPrefix);
-		});
-		return errors.reduce((arr, items) => {
-			return arr.concat(items);
-		}, []);
-	} else {
-		return validateObject(schema, options);
-	}
-};
-
-const validateObject = (schema, options) => {
-	const validate = ajv.compile(schema);
-	const valid = validate(options);
-	return valid ? [] : filterErrors(validate.errors);
-};
-
-const filterErrors = errors => {
-	let newErrors = [];
-	for (const err of errors) {
-		const dataPath = err.dataPath;
-		let children = [];
-		newErrors = newErrors.filter(oldError => {
-			if (oldError.dataPath.includes(dataPath)) {
-				if (oldError.children) {
-					children = children.concat(oldError.children.slice(0));
-				}
-				oldError.children = undefined;
-				children.push(oldError);
-				return false;
+	validate(schema, options, {
+		name: "Webpack",
+		postFormatter: (formattedError, error) => {
+			if (
+				error.children &&
+				error.children.some(
+					child =>
+						child.keyword === "absolutePath" &&
+						child.dataPath === ".output.filename"
+				)
+			) {
+				return `${formattedError}\nPlease use output.path to specify absolute path and output.filename for the file name.`;
 			}
-			return true;
-		});
-		if (children.length) {
-			err.children = children;
+
+			if (error.keyword === "additionalProperties" && !error.dataPath) {
+				if (error.params.additionalProperty === "debug") {
+					return (
+						`${formattedError}\n` +
+						"The 'debug' property was removed in webpack 2.0.0.\n" +
+						"Loaders should be updated to allow passing this option via loader options in module.rules.\n" +
+						"Until loaders are updated one can use the LoaderOptionsPlugin to switch loaders into debug mode:\n" +
+						"plugins: [\n" +
+						"  new webpack.LoaderOptionsPlugin({\n" +
+						"    debug: true\n" +
+						"  })\n" +
+						"]"
+					);
+				}
+
+				if (error.params.additionalProperty) {
+					return (
+						`${formattedError}\n` +
+						"For typos: please correct them.\n" +
+						"For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.\n" +
+						"  Loaders should be updated to allow passing options via loader options in module.rules.\n" +
+						"  Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:\n" +
+						"  plugins: [\n" +
+						"    new webpack.LoaderOptionsPlugin({\n" +
+						"      // test: /\\.xxx$/, // may apply this only for some modules\n" +
+						"      options: {\n" +
+						`        ${error.params.additionalProperty}: …\n` +
+						"      }\n" +
+						"    })\n" +
+						"  ]"
+					);
+				}
+			}
+
+			return formattedError;
 		}
-		newErrors.push(err);
-	}
-
-	return newErrors;
+	});
 };
-
 module.exports = validateSchema;
diff --git a/lib/webpack.js b/lib/webpack.js
index 66fa35711..7d2a6b729 100644
--- a/lib/webpack.js
+++ b/lib/webpack.js
@@ -10,7 +10,6 @@ const Compiler = require("./Compiler");
 const MultiCompiler = require("./MultiCompiler");
 const WebpackOptionsApply = require("./WebpackOptionsApply");
 const WebpackOptionsDefaulter = require("./WebpackOptionsDefaulter");
-const WebpackOptionsValidationError = require("./WebpackOptionsValidationError");
 const NodeEnvironmentPlugin = require("./node/NodeEnvironmentPlugin");
 const validateSchema = require("./validateSchema");
 
@@ -76,10 +75,7 @@ const createCompiler = options => {
  * @returns {Compiler | MultiCompiler} the compiler object
  */
 const webpack = (options, callback) => {
-	const validationErrors = validateSchema(webpackOptionsSchema, options);
-	if (validationErrors.length) {
-		throw new WebpackOptionsValidationError(validationErrors);
-	}
+	validateSchema(webpackOptionsSchema, options);
 	/** @type {TODO} */
 	let compiler;
 	let watch = false;
diff --git a/package.json b/package.json
index 2a0d729cb..80176781c 100644
--- a/package.json
+++ b/package.json
@@ -10,8 +10,6 @@
     "@webassemblyjs/wasm-edit": "1.8.5",
     "@webassemblyjs/wasm-parser": "1.8.5",
     "acorn": "^6.2.1",
-    "ajv": "^6.10.2",
-    "ajv-keywords": "^3.4.1",
     "chrome-trace-event": "^1.0.2",
     "enhanced-resolve": "5.0.0-beta.2",
     "eslint-scope": "^5.0.0",
@@ -23,7 +21,7 @@
     "loader-runner": "3.0.0",
     "loader-utils": "^1.2.3",
     "neo-async": "^2.6.1",
-    "schema-utils": "^1.0.0",
+    "schema-utils": "^2.1.0",
     "tapable": "2.0.0-beta.8",
     "terser-webpack-plugin": "^1.4.1",
     "watchpack": "2.0.0-beta.7",
diff --git a/schemas/ajv.absolutePath.js b/schemas/ajv.absolutePath.js
deleted file mode 100644
index 8ef11f435..000000000
--- a/schemas/ajv.absolutePath.js
+++ /dev/null
@@ -1,55 +0,0 @@
-"use strict";
-
-const errorMessage = (schema, data, message) => ({
-	keyword: "absolutePath",
-	params: { absolutePath: data },
-	message: message,
-	parentSchema: schema
-});
-
-const getErrorFor = (shouldBeAbsolute, data, schema) => {
-	const message = shouldBeAbsolute
-		? `The provided value ${JSON.stringify(data)} is not an absolute path!`
-		: `A relative path is expected. However, the provided value ${JSON.stringify(
-				data
-		  )} is an absolute path!`;
-
-	return errorMessage(schema, data, message);
-};
-
-module.exports = ajv =>
-	ajv.addKeyword("absolutePath", {
-		errors: true,
-		type: "string",
-		compile(expected, schema) {
-			function callback(data) {
-				let passes = true;
-				const isExclamationMarkPresent = data.includes("!");
-				const isCorrectAbsoluteOrRelativePath =
-					expected === /^(?:[A-Za-z]:\\|\/)/.test(data);
-
-				if (isExclamationMarkPresent) {
-					callback.errors = [
-						errorMessage(
-							schema,
-							data,
-							`The provided value ${JSON.stringify(
-								data
-							)} contains exclamation mark (!) which is not allowed because it's reserved for loader syntax.`
-						)
-					];
-					passes = false;
-				}
-
-				if (!isCorrectAbsoluteOrRelativePath) {
-					callback.errors = [getErrorFor(expected, data, schema)];
-					passes = false;
-				}
-
-				return passes;
-			}
-			callback.errors = [];
-
-			return callback;
-		}
-	});
diff --git a/schemas/plugins/WatchIgnorePlugin.json b/schemas/plugins/WatchIgnorePlugin.json
index b08d50ba6..2acb7e78c 100644
--- a/schemas/plugins/WatchIgnorePlugin.json
+++ b/schemas/plugins/WatchIgnorePlugin.json
@@ -1,18 +1,25 @@
 {
   "title": "WatchIgnorePluginOptions",
-  "description": "A list of RegExps or absolute paths to directories or files that should be ignored",
-  "type": "array",
-  "items": {
-    "description": "RegExp or absolute path to directories or files that should be ignored",
-    "oneOf": [
-      {
-        "type": "string"
+  "type": "object",
+  "additionalProperties": false,
+  "properties": {
+    "paths": {
+      "description": "A list of RegExps or absolute paths to directories or files that should be ignored",
+      "type": "array",
+      "items": {
+        "description": "RegExp or absolute path to directories or files that should be ignored",
+        "oneOf": [
+          {
+            "type": "string"
+          },
+          {
+            "instanceof": "RegExp",
+            "tsType": "RegExp"
+          }
+        ]
       },
-      {
-        "instanceof": "RegExp",
-        "tsType": "RegExp"
-      }
-    ]
+      "minItems": 1
+    }
   },
-  "minItems": 1
+  "required": ["paths"]
 }
diff --git a/schemas/plugins/debug/ProfilingPlugin.json b/schemas/plugins/debug/ProfilingPlugin.json
index e9a4bf18b..4de19e564 100644
--- a/schemas/plugins/debug/ProfilingPlugin.json
+++ b/schemas/plugins/debug/ProfilingPlugin.json
@@ -4,10 +4,9 @@
   "additionalProperties": false,
   "properties": {
     "outputPath": {
-      "description": "Path to the output file e.g. `profiling/events.json`. Defaults to `events.json`.",
+      "description": "Path to the output file e.g. `path.resolve(__dirname, 'profiling/events.json')`. Defaults to `events.json`.",
       "type": "string",
-      "absolutePath": false,
-      "minLength": 4
+      "absolutePath": true
     }
   }
 }
diff --git a/test/ProfilingPlugin.unittest.js b/test/ProfilingPlugin.unittest.js
index 0528c9ecb..b56bb8330 100644
--- a/test/ProfilingPlugin.unittest.js
+++ b/test/ProfilingPlugin.unittest.js
@@ -1,13 +1,15 @@
 "use strict";
 
+const path = require("path");
 const ProfilingPlugin = require("../lib/debug/ProfilingPlugin");
 
 describe("Profiling Plugin", () => {
 	it("should persist the passed outpath", () => {
+		const outputPath = path.join(__dirname, "invest_in_doge_coin");
 		const plugin = new ProfilingPlugin({
-			outputPath: "invest_in_doge_coin"
+			outputPath: outputPath
 		});
-		expect(plugin.outputPath).toBe("invest_in_doge_coin");
+		expect(plugin.outputPath).toBe(outputPath);
 	});
 
 	it("should handle no options", () => {
diff --git a/test/Validation.test.js b/test/Validation.test.js
index d7f7e1594..15f7caeb8 100644
--- a/test/Validation.test.js
+++ b/test/Validation.test.js
@@ -8,7 +8,7 @@ describe("Validation", () => {
 			try {
 				webpack(config);
 			} catch (err) {
-				if (err.name !== "WebpackOptionsValidationError") throw err;
+				if (err.name !== "ValidationError") throw err;
 
 				expect(err.message).toMatch(/^Invalid configuration object./);
 				fn(err.message);
@@ -22,16 +22,18 @@ describe("Validation", () => {
 
 	createTestCase("undefined configuration", undefined, msg =>
 		expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration should be an object."
-`)
+		"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+		 - configuration should be an object:
+		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }"
+	`)
 	);
 
 	createTestCase("null configuration", null, msg =>
 		expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration should be an object."
-`)
+		"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+		 - configuration should be an object:
+		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }"
+	`)
 	);
 
 	createTestCase(
@@ -41,10 +43,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.entry should be an non-empty string.
-   -> An entry point without name. The string is resolved to a module which is loaded upon startup."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.entry should be an non-empty string.
+			   -> An entry point without name. The string is resolved to a module which is loaded upon startup."
+		`)
 	);
 
 	createTestCase(
@@ -56,10 +58,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.entry['bundle'] should be an non-empty array.
-   -> A non-empty array of non-empty strings"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.entry['bundle'] should be an non-empty array.
+			   -> A non-empty array of non-empty strings"
+		`)
 	);
 
 	createTestCase(
@@ -72,10 +74,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.module.wrappedContextRegExp should be an instance of RegExp
-   -> Set the inner regular expression for partial dynamic dependencies"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.module.wrappedContextRegExp should be an instance of RegExp
+			   -> Set the inner regular expression for partial dynamic dependencies."
+		`)
 	);
 
 	createTestCase(
@@ -86,10 +88,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.parallelism should be >= 1.
-   -> The number of parallel processed modules in the compilation."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.parallelism should be >= 1.
+			   -> The number of parallel processed modules in the compilation."
+		`)
 	);
 
 	createTestCase(
@@ -99,10 +101,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.entry should not contain the item 'abc' twice.
-   -> A non-empty array of non-empty strings"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.entry should not contain the item 'abc' twice.
+			   -> A non-empty array of non-empty strings"
+		`)
 	);
 
 	createTestCase(
@@ -115,16 +117,16 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.entry[0] should be a string.
-   -> A non-empty string
- - configuration.output.filename should be one of these:
-   non-empty string | function
-   -> Specifies the name of each output file on disk. You must **not** specify an absolute path here! The \`output.path\` option determines the location on disk the files are written to, filename is used solely for naming the individual files.
-   Details:
-    * configuration.output.filename should be a string.
-    * configuration.output.filename should be an instance of function"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.entry[0] should be a non-empty string.
+			   -> A non-empty string
+			 - configuration.output.filename should be one of these:
+			   non-empty string | function
+			   -> Specifies the name of each output file on disk. You must **not** specify an absolute path here! The \`output.path\` option determines the location on disk the files are written to, filename is used solely for naming the individual files.
+			   Details:
+			    * configuration.output.filename should be a non-empty string.
+			    * configuration.output.filename should be an instance of function."
+		`)
 	);
 
 	createTestCase(
@@ -142,16 +144,16 @@ describe("Validation", () => {
 		],
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration[0].entry[0] should be a string.
-   -> A non-empty string
- - configuration[1].output.filename should be one of these:
-   non-empty string | function
-   -> Specifies the name of each output file on disk. You must **not** specify an absolute path here! The \`output.path\` option determines the location on disk the files are written to, filename is used solely for naming the individual files.
-   Details:
-    * configuration[1].output.filename should be a string.
-    * configuration[1].output.filename should be an instance of function"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration[0].entry[0] should be a non-empty string.
+			   -> A non-empty string
+			 - configuration[1].output.filename should be one of these:
+			   non-empty string | function
+			   -> Specifies the name of each output file on disk. You must **not** specify an absolute path here! The \`output.path\` option determines the location on disk the files are written to, filename is used solely for naming the individual files.
+			   Details:
+			    * configuration[1].output.filename should be a non-empty string.
+			    * configuration[1].output.filename should be an instance of function."
+		`)
 	);
 
 	createTestCase(
@@ -175,11 +177,11 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.module.rules[0].oneOf[0] has an unknown property 'passer'. These properties are valid:
-   object { compiler?, enforce?, exclude?, include?, issuer?, loader?, oneOf?, options?, parser?, realResource?, resolve?, resource?, resourceQuery?, rules?, sideEffects?, test?, type?, use? }
-   -> A rule"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.module.rules[0].oneOf[0] has an unknown property 'passer'. These properties are valid:
+			   object { compiler?, enforce?, exclude?, include?, issuer?, loader?, oneOf?, options?, parser?, realResource?, resolve?, resource?, resourceQuery?, rules?, sideEffects?, test?, type?, use? }
+			   -> A rule"
+		`)
 	);
 
 	createTestCase(
@@ -190,22 +192,22 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration has an unknown property 'postcss'. These properties are valid:
-   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }
-   For typos: please correct them.
-   For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.
-     Loaders should be updated to allow passing options via loader options in module.rules.
-     Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:
-     plugins: [
-       new webpack.LoaderOptionsPlugin({
-         // test: /\\\\.xxx$/, // may apply this only for some modules
-         options: {
-           postcss: …
-         }
-       })
-     ]"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration has an unknown property 'postcss'. These properties are valid:
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }
+			   For typos: please correct them.
+			   For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.
+			     Loaders should be updated to allow passing options via loader options in module.rules.
+			     Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:
+			     plugins: [
+			       new webpack.LoaderOptionsPlugin({
+			         // test: /\\\\.xxx$/, // may apply this only for some modules
+			         options: {
+			           postcss: …
+			         }
+			       })
+			     ]"
+		`)
 	);
 
 	createTestCase(
@@ -216,14 +218,14 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.devtool should be one of these:
-   string | false
-   -> A developer tool to enhance debugging.
-   Details:
-    * configuration.devtool should be a string.
-    * configuration.devtool should be false"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.devtool should be one of these:
+			   string | false
+			   -> A developer tool to enhance debugging.
+			   Details:
+			    * configuration.devtool should be a string.
+			    * configuration.devtool should be false."
+		`)
 	);
 
 	createTestCase(
@@ -237,10 +239,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.output.path: The provided value \\"/somepath/!test\\" contains exclamation mark (!) which is not allowed because it's reserved for loader syntax.
-   -> The output directory as **absolute path** (required)."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.output.path: The provided value \\"/somepath/!test\\" contains exclamation mark (!) which is not allowed because it's reserved for loader syntax.
+			   -> The output directory as **absolute path** (required)."
+		`)
 	);
 
 	createTestCase(
@@ -253,10 +255,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.output.filename: A relative path is expected. However, the provided value \\"/bar\\" is an absolute path!
-   Please use output.path to specify absolute path and output.filename for the file name."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.output.filename: A relative path is expected. However, the provided value \\"/bar\\" is an absolute path!
+			   Please use output.path to specify absolute path and output.filename for the file name."
+		`)
 	);
 
 	createTestCase(
@@ -270,10 +272,10 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.context: The provided value \\"baz\\" is not an absolute path!
-   -> The base directory (absolute path!) for resolving the \`entry\` option. If \`output.pathinfo\` is set, the included pathinfo is shortened to this directory."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.context: The provided value \\"baz\\" is not an absolute path!
+			   -> The base directory (absolute path!) for resolving the \`entry\` option. If \`output.pathinfo\` is set, the included pathinfo is shortened to this directory."
+		`)
 	);
 
 	createTestCase(
@@ -290,10 +292,10 @@ describe("Validation", () => {
 					.replace(/object \{ .* \}/g, "object {...}")
 					.replace(/"none" \| .+/g, '"none" | ...')
 			).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.stats has an unknown property 'foobar'. These properties are valid:
-   object {...}"
-`);
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.stats has an unknown property 'foobar'. These properties are valid:
+			   object {...}"
+		`);
 		}
 	);
 
@@ -305,16 +307,17 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.plugins[0] should be one of these:
-   object { apply, … } | function
-   -> Plugin of type object or instanceof Function
-   Details:
-    * configuration.plugins[0] should be an object.
-      -> Plugin instance
-    * configuration.plugins[0] should be an instance of function
-      -> Function acting as plugin"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.plugins[0] should be one of these:
+			   object { apply, … } | function
+			   -> Plugin of type object or instanceof Function
+			   Details:
+			    * configuration.plugins[0] should be an object:
+			      object { apply, … }
+			      -> Plugin instance
+			    * configuration.plugins[0] should be an instance of function
+			      -> Function acting as plugin."
+		`)
 	);
 
 	createTestCase(
@@ -325,16 +328,17 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.plugins[0] should be one of these:
-   object { apply, … } | function
-   -> Plugin of type object or instanceof Function
-   Details:
-    * configuration.plugins[0] should be an object.
-      -> Plugin instance
-    * configuration.plugins[0] should be an instance of function
-      -> Function acting as plugin"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.plugins[0] should be one of these:
+			   object { apply, … } | function
+			   -> Plugin of type object or instanceof Function
+			   Details:
+			    * configuration.plugins[0] should be an object:
+			      object { apply, … }
+			      -> Plugin instance
+			    * configuration.plugins[0] should be an instance of function
+			      -> Function acting as plugin."
+		`)
 	);
 
 	createTestCase(
@@ -345,16 +349,17 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.plugins[0] should be one of these:
-   object { apply, … } | function
-   -> Plugin of type object or instanceof Function
-   Details:
-    * configuration.plugins[0] should be an object.
-      -> Plugin instance
-    * configuration.plugins[0] should be an instance of function
-      -> Function acting as plugin"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.plugins[0] should be one of these:
+			   object { apply, … } | function
+			   -> Plugin of type object or instanceof Function
+			   Details:
+			    * configuration.plugins[0] should be an object:
+			      object { apply, … }
+			      -> Plugin instance
+			    * configuration.plugins[0] should be an instance of function
+			      -> Function acting as plugin."
+		`)
 	);
 
 	createTestCase(
@@ -365,16 +370,17 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.plugins[0] should be one of these:
-   object { apply, … } | function
-   -> Plugin of type object or instanceof Function
-   Details:
-    * configuration.plugins[0] should be an object.
-      -> Plugin instance
-    * configuration.plugins[0] should be an instance of function
-      -> Function acting as plugin"
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.plugins[0] should be one of these:
+			   object { apply, … } | function
+			   -> Plugin of type object or instanceof Function
+			   Details:
+			    * configuration.plugins[0] should be an object:
+			      object { apply, … }
+			      -> Plugin instance
+			    * configuration.plugins[0] should be an instance of function
+			      -> Function acting as plugin."
+		`)
 	);
 
 	createTestCase(
@@ -385,11 +391,11 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.plugins[0] misses the property 'apply'.
-   function
-   -> The run point of the plugin, required method."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.plugins[0] misses the property 'apply'. Should be:
+			   function
+			   -> The run point of the plugin, required method."
+		`)
 	);
 
 	createTestCase(
@@ -399,11 +405,32 @@ describe("Validation", () => {
 		},
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration.mode should be one of these:
-   \\"development\\" | \\"production\\" | \\"none\\"
-   -> Enable production optimizations or development hints."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration.mode should be one of these:
+			   \\"development\\" | \\"production\\" | \\"none\\"
+			   -> Enable production optimizations or development hints."
+		`)
+	);
+
+	createTestCase(
+		"debug",
+		{
+			debug: true
+		},
+		msg =>
+			expect(msg).toMatchInlineSnapshot(`
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration has an unknown property 'debug'. These properties are valid:
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }
+			   The 'debug' property was removed in webpack 2.0.0.
+			   Loaders should be updated to allow passing this option via loader options in module.rules.
+			   Until loaders are updated one can use the LoaderOptionsPlugin to switch loaders into debug mode:
+			   plugins: [
+			     new webpack.LoaderOptionsPlugin({
+			       debug: true
+			     })
+			   ]"
+		`)
 	);
 
 	createTestCase(
@@ -420,8 +447,9 @@ describe("Validation", () => {
 		],
 		msg =>
 			expect(msg).toMatchInlineSnapshot(`
-"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
- - configuration[1] should be an object."
-`)
+			"Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
+			 - configuration[1] should be an object:
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }"
+		`)
 	);
 });
diff --git a/test/watchCases/plugins/watch-ignore-plugin/webpack.config.js b/test/watchCases/plugins/watch-ignore-plugin/webpack.config.js
index a24d87e2f..81c7a169c 100644
--- a/test/watchCases/plugins/watch-ignore-plugin/webpack.config.js
+++ b/test/watchCases/plugins/watch-ignore-plugin/webpack.config.js
@@ -1,5 +1,5 @@
 var webpack = require("../../../../");
 
 module.exports = {
-	plugins: [new webpack.WatchIgnorePlugin([/file\.js$/, /foo$/])]
+	plugins: [new webpack.WatchIgnorePlugin({ paths: [/file\.js$/, /foo$/] })]
 };
diff --git a/yarn.lock b/yarn.lock
index 14a387145..da4001348 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -694,7 +694,7 @@ ajv-errors@^1.0.0:
   resolved "https://registry.yarnpkg.com/ajv-errors/-/ajv-errors-1.0.1.tgz#f35986aceb91afadec4102fbd85014950cefa64d"
   integrity sha512-DCRfO/4nQ+89p/RK43i8Ezd41EqdGIU4ld7nGF8OQ14oc/we5rEntLCUa7+jrn3nn83BosfwZA0wb4pon2o8iQ==
 
-ajv-keywords@^3.1.0, ajv-keywords@^3.4.1:
+ajv-keywords@^3.1.0:
   version "3.4.1"
   resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-3.4.1.tgz#ef916e271c64ac12171fd8384eaae6b2345854da"
   integrity sha512-RO1ibKvd27e6FEShVFfPALuHI3WjSVNeK5FIsmme/LYRNxjKuNj+Dt7bucLa6NdSv3JcVTyMlm9kGR84z1XpaQ==
@@ -5627,6 +5627,14 @@ schema-utils@^2.0.0, schema-utils@^2.0.1:
     ajv "^6.1.0"
     ajv-keywords "^3.1.0"
 
+schema-utils@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-2.1.0.tgz#940363b6b1ec407800a22951bdcc23363c039393"
+  integrity sha512-g6SViEZAfGNrToD82ZPUjq52KUPDYc+fN5+g6Euo5mLokl/9Yx14z0Cu4RR1m55HtBXejO0sBt+qw79axN+Fiw==
+  dependencies:
+    ajv "^6.1.0"
+    ajv-keywords "^3.1.0"
+
 script-loader@~0.7.0:
   version "0.7.2"
   resolved "https://registry.yarnpkg.com/script-loader/-/script-loader-0.7.2.tgz#2016db6f86f25f5cf56da38915d83378bb166ba7"