diff --git a/lib/CaseSensitiveModulesWarning.js b/lib/CaseSensitiveModulesWarning.js
index 6ae4d0376..265060c4e 100644
--- a/lib/CaseSensitiveModulesWarning.js
+++ b/lib/CaseSensitiveModulesWarning.js
@@ -36,9 +36,9 @@ const createModulesListMessage = (modules, moduleGraph) => {
 	return modules
 		.map(m => {
 			let message = `* ${m.identifier()}`;
-			const validReasons = moduleGraph
-				.getIncomingConnections(m)
-				.filter(reason => reason.originModule);
+			const validReasons = Array.from(
+				moduleGraph.getIncomingConnections(m)
+			).filter(reason => reason.originModule);
 
 			if (validReasons.length > 0) {
 				message += `\n    Used by ${validReasons.length} module(s), i. e.`;
diff --git a/lib/LibManifestPlugin.js b/lib/LibManifestPlugin.js
index e1b54916c..2bdb2e948 100644
--- a/lib/LibManifestPlugin.js
+++ b/lib/LibManifestPlugin.js
@@ -19,6 +19,19 @@ const { dirname, mkdirp } = require("./util/fs");
  * @property {boolean | string[]} exports
  */
 
+/**
+ * @template T
+ * @param {Iterable<T>} iterable iterable
+ * @param {function(T): boolean} filter predicate
+ * @returns {boolean} true, if some items match the filter predicate
+ */
+const someInIterable = (iterable, filter) => {
+	for (const item of iterable) {
+		if (filter(item)) return true;
+	}
+	return false;
+};
+
 class LibManifestPlugin {
 	constructor(options) {
 		this.options = options;
@@ -60,9 +73,10 @@ class LibManifestPlugin {
 								module => {
 									if (
 										this.options.entryOnly &&
-										!moduleGraph
-											.getIncomingConnections(module)
-											.some(c => c.dependency instanceof EntryDependency)
+										!someInIterable(
+											moduleGraph.getIncomingConnections(module),
+											c => c.dependency instanceof EntryDependency
+										)
 									) {
 										return;
 									}
diff --git a/lib/Module.js b/lib/Module.js
index 62e92b7db..62ca73663 100644
--- a/lib/Module.js
+++ b/lib/Module.js
@@ -339,11 +339,12 @@ class Module extends DependenciesBlock {
 	 * @returns {boolean} true, if the module is optional
 	 */
 	isOptional(moduleGraph) {
-		const connections = moduleGraph.getIncomingConnections(this);
-		return (
-			connections.length > 0 &&
-			connections.every(r => r.dependency && r.dependency.optional && r.active)
-		);
+		let hasConnections = false;
+		for (const r of moduleGraph.getIncomingConnections(this)) {
+			if (!r.dependency || !r.dependency.optional || !r.active) return false;
+			hasConnections = true;
+		}
+		return hasConnections;
 	}
 
 	/**
@@ -413,7 +414,10 @@ class Module extends DependenciesBlock {
 	 * @returns {boolean} true if at least one other module depends on this module
 	 */
 	hasReasons(moduleGraph) {
-		return moduleGraph.getIncomingConnections(this).some(c => c.active);
+		for (const c of moduleGraph.getIncomingConnections(this)) {
+			if (c.active) return true;
+		}
+		return false;
 	}
 
 	/**
diff --git a/lib/ModuleGraph.js b/lib/ModuleGraph.js
index 12ade91ad..4697fa213 100644
--- a/lib/ModuleGraph.js
+++ b/lib/ModuleGraph.js
@@ -967,20 +967,20 @@ class ModuleGraph {
 
 	/**
 	 * @param {Module} module the module
-	 * @returns {ModuleGraphConnection[]} reasons why a module is included
+	 * @returns {Iterable<ModuleGraphConnection>} reasons why a module is included
 	 */
 	getIncomingConnections(module) {
 		const connections = this._getModuleGraphModule(module).incomingConnections;
-		return Array.from(connections);
+		return connections;
 	}
 
 	/**
 	 * @param {Module} module the module
-	 * @returns {ModuleGraphConnection[]} list of outgoing connections
+	 * @returns {Iterable<ModuleGraphConnection>} list of outgoing connections
 	 */
 	getOutgoingConnections(module) {
 		const connections = this._getModuleGraphModule(module).outgoingConnections;
-		return Array.from(connections);
+		return connections;
 	}
 
 	/**
diff --git a/lib/ids/OccurrenceModuleIdsPlugin.js b/lib/ids/OccurrenceModuleIdsPlugin.js
index d39493dd6..4394dd1f1 100644
--- a/lib/ids/OccurrenceModuleIdsPlugin.js
+++ b/lib/ids/OccurrenceModuleIdsPlugin.js
@@ -97,8 +97,7 @@ class OccurrenceModuleIdsPlugin {
 				if (prioritiseInitial) {
 					for (const m of modulesInOccurrenceOrder) {
 						const result =
-							moduleGraph
-								.getIncomingConnections(m)
+							Array.from(moduleGraph.getIncomingConnections(m))
 								.filter(c => c.active)
 								.reduce(countOccursInEntry, 0) +
 							initialChunkChunkMap.get(m) +
@@ -109,8 +108,7 @@ class OccurrenceModuleIdsPlugin {
 
 				for (const m of modules) {
 					const result =
-						moduleGraph
-							.getIncomingConnections(m)
+						Array.from(moduleGraph.getIncomingConnections(m))
 							.filter(c => c.active)
 							.reduce(countOccurs, 0) +
 						chunkGraph.getNumberOfModuleChunks(m) +
diff --git a/lib/javascript/JavascriptModulesPlugin.js b/lib/javascript/JavascriptModulesPlugin.js
index b880476af..36950855c 100644
--- a/lib/javascript/JavascriptModulesPlugin.js
+++ b/lib/javascript/JavascriptModulesPlugin.js
@@ -34,6 +34,19 @@ const JavascriptParser = require("./JavascriptParser");
 /** @typedef {import("../RuntimeTemplate")} RuntimeTemplate */
 /** @typedef {import("../util/Hash")} Hash */
 
+/**
+ * @template T
+ * @param {Iterable<T>} iterable iterable
+ * @param {function(T): boolean} filter predicate
+ * @returns {boolean} true, if some items match the filter predicate
+ */
+const someInIterable = (iterable, filter) => {
+	for (const item of iterable) {
+		if (filter(item)) return true;
+	}
+	return false;
+};
+
 /**
  * @param {Chunk} chunk a chunk
  * @param {ChunkGraph} chunkGraph the chunk graph
@@ -729,9 +742,10 @@ class JavascriptModulesPlugin {
 				)) {
 					if (
 						result.allowInlineStartup &&
-						moduleGraph
-							.getIncomingConnections(entryModule)
-							.some(c => c.originModule && c.active)
+						someInIterable(
+							moduleGraph.getIncomingConnections(entryModule),
+							c => c.originModule && c.active
+						)
 					) {
 						buf2.push(
 							"// This entry module is referenced by other modules so it can't be inlined"
diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
index 1cae08f0a..75d30b2aa 100644
--- a/lib/optimize/ConcatenatedModule.js
+++ b/lib/optimize/ConcatenatedModule.js
@@ -738,8 +738,7 @@ class ConcatenatedModule extends Module {
 		 * @returns {(function(): Module)[]} imported modules in order
 		 */
 		const getConcatenatedImports = module => {
-			const references = moduleGraph
-				.getOutgoingConnections(module)
+			const references = Array.from(moduleGraph.getOutgoingConnections(module))
 				.filter(connection => {
 					if (!(connection.dependency instanceof HarmonyImportDependency))
 						return false;
diff --git a/lib/optimize/ModuleConcatenationPlugin.js b/lib/optimize/ModuleConcatenationPlugin.js
index a273e0ed4..80c025909 100644
--- a/lib/optimize/ModuleConcatenationPlugin.js
+++ b/lib/optimize/ModuleConcatenationPlugin.js
@@ -173,9 +173,9 @@ class ModuleConcatenationPlugin {
 								continue;
 							}
 
-							const incomingConnections = moduleGraph
-								.getIncomingConnections(module)
-								.filter(connection => connection.active);
+							const incomingConnections = Array.from(
+								moduleGraph.getIncomingConnections(module)
+							).filter(connection => connection.active);
 
 							// Module must only be used by Harmony Imports
 							const nonHarmonyConnections = incomingConnections.filter(
diff --git a/lib/stats/DefaultStatsFactoryPlugin.js b/lib/stats/DefaultStatsFactoryPlugin.js
index b741f85a5..cb78a3512 100644
--- a/lib/stats/DefaultStatsFactoryPlugin.js
+++ b/lib/stats/DefaultStatsFactoryPlugin.js
@@ -631,7 +631,7 @@ const SIMPLE_EXTRACTORS = {
 			} = context;
 			object.reasons = factory.create(
 				`${type}.reasons`,
-				moduleGraph.getIncomingConnections(module),
+				Array.from(moduleGraph.getIncomingConnections(module)),
 				context
 			);
 		},
@@ -889,8 +889,9 @@ const SIMPLE_EXTRACTORS = {
 			object.originName = origin.readableIdentifier(requestShortener);
 			object.moduleIdentifier = module.identifier();
 			object.moduleName = module.readableIdentifier(requestShortener);
-			const dependencies = moduleGraph
-				.getIncomingConnections(module)
+			const dependencies = Array.from(
+				moduleGraph.getIncomingConnections(module)
+			)
 				.filter(c => c.resolvedOriginModule === origin && c.dependency)
 				.map(c => c.dependency);
 			object.dependencies = factory.create(