diff --git a/.luacheckrc b/.luacheckrc
index f350ff014a..b945835bba 100644
--- a/.luacheckrc
+++ b/.luacheckrc
@@ -11,6 +11,7 @@ cache = true
 
 ignore = {
   "631",  -- max_line_length
+  "212/_.*",  -- unused argument, for vars with "_" prefix
 }
 
 -- Global objects defined by the C code
diff --git a/busted/outputHandlers/TAP.lua b/busted/outputHandlers/TAP.lua
deleted file mode 100644
index 612e633576..0000000000
--- a/busted/outputHandlers/TAP.lua
+++ /dev/null
@@ -1,94 +0,0 @@
--- TODO(jkeyes): Use the upstream version when busted releases it. (But how to
--- inject our call to global_helpers.read_nvim_log() ?)
-
-local pretty = require 'pl.pretty'
-local global_helpers = require('test.helpers')
-
-return function(options)
-  local busted = require 'busted'
-  local handler = require 'busted.outputHandlers.base'()
-
-  local success = 'ok %u - %s'
-  local failure = 'not ' .. success
-  local skip = 'ok %u - # SKIP %s'
-  local counter = 0
-
-  handler.suiteReset = function()
-    counter = 0
-    return nil, true
-  end
-
-  handler.suiteEnd = function()
-    io.write(global_helpers.read_nvim_log())
-    print('1..' .. counter)
-    io.flush()
-    return nil, true
-  end
-
-  local function showFailure(t)
-    local message = t.message
-    local trace = t.trace or {}
-
-    if message == nil then
-      message = 'Nil error'
-    elseif type(message) ~= 'string' then
-      message = pretty.write(message)
-    end
-
-    print(failure:format(counter, t.name))
-    print('# ' .. t.element.trace.short_src .. ' @ ' .. t.element.trace.currentline)
-    if t.randomseed then print('# Random seed: ' .. t.randomseed) end
-    print('# Failure message: ' .. message:gsub('\n', '\n# '))
-    if options.verbose and trace.traceback then
-      print('# ' .. trace.traceback:gsub('^\n', '', 1):gsub('\n', '\n# '))
-    end
-  end
-
-  handler.testStart = function(element, parent)
-    local trace = element.trace
-    if options.verbose and trace and trace.short_src then
-      local fileline = trace.short_src .. ' @ ' ..  trace.currentline .. ': '
-      local testName = fileline .. handler.getFullName(element)
-      print('# ' .. testName)
-    end
-    io.flush()
-
-    return nil, true
-  end
-
-  handler.testEnd = function(element, parent, status, trace)
-    counter = counter + 1
-    if status == 'success' then
-      local t = handler.successes[#handler.successes]
-      print(success:format(counter, t.name))
-    elseif status == 'pending' then
-      local t = handler.pendings[#handler.pendings]
-      print(skip:format(counter, (t.message or t.name)))
-    elseif status == 'failure' then
-      showFailure(handler.failures[#handler.failures])
-    elseif status == 'error' then
-      showFailure(handler.errors[#handler.errors])
-    end
-    io.flush()
-
-    return nil, true
-  end
-
-  handler.error = function(element, parent, message, debug)
-    if element.descriptor ~= 'it' then
-      counter = counter + 1
-      showFailure(handler.errors[#handler.errors])
-    end
-    io.flush()
-
-    return nil, true
-  end
-
-  busted.subscribe({ 'suite', 'reset' }, handler.suiteReset)
-  busted.subscribe({ 'suite', 'end' }, handler.suiteEnd)
-  busted.subscribe({ 'test', 'start' }, handler.testStart, { predicate = handler.cancelOnPending })
-  busted.subscribe({ 'test', 'end' }, handler.testEnd, { predicate = handler.cancelOnPending })
-  busted.subscribe({ 'error' }, handler.error)
-
-  return handler
-end
diff --git a/cmake/RunTests.cmake b/cmake/RunTests.cmake
index f5b3f01778..5406a07fc8 100644
--- a/cmake/RunTests.cmake
+++ b/cmake/RunTests.cmake
@@ -43,7 +43,7 @@ execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory $ENV{TMPDIR})
 
 set(ENV{SYSTEM_NAME} ${CMAKE_HOST_SYSTEM_NAME})  # used by test/helpers.lua.
 execute_process(
-  COMMAND ${BUSTED_PRG} -v -o ${BUSTED_OUTPUT_TYPE}
+  COMMAND ${BUSTED_PRG} -v -o test.busted.outputHandlers.${BUSTED_OUTPUT_TYPE}
     --lazy --helper=${TEST_DIR}/${TEST_TYPE}/preload.lua
     --lpath=${BUILD_DIR}/?.lua
     --lpath=${WORKING_DIR}/runtime/lua/?.lua
diff --git a/test/busted/outputHandlers/TAP.lua b/test/busted/outputHandlers/TAP.lua
new file mode 100644
index 0000000000..3dd171dc1b
--- /dev/null
+++ b/test/busted/outputHandlers/TAP.lua
@@ -0,0 +1,14 @@
+-- Extends the upstream TAP handler, to display the log with suiteEnd.
+
+local global_helpers = require('test.helpers')
+
+return function(options)
+  local handler = require 'busted.outputHandlers.TAP'(options)
+
+  handler.suiteEnd = function()
+    io.write(global_helpers.read_nvim_log())
+    return handler.suiteEnd()
+  end
+
+  return handler
+end
diff --git a/busted/outputHandlers/nvim.lua b/test/busted/outputHandlers/nvim.lua
similarity index 94%
rename from busted/outputHandlers/nvim.lua
rename to test/busted/outputHandlers/nvim.lua
index d137300a7e..1b500fc999 100644
--- a/busted/outputHandlers/nvim.lua
+++ b/test/busted/outputHandlers/nvim.lua
@@ -1,6 +1,4 @@
-local s = require 'say'
 local pretty = require 'pl.pretty'
-local term = require 'term'
 local global_helpers = require('test.helpers')
 
 local colors
@@ -65,8 +63,6 @@ return function(options)
     },
   }
 
-  c = nil
-
   local fileCount = 0
   local fileTestCount = 0
   local testCount = 0
@@ -76,7 +72,6 @@ return function(options)
   local errorCount = 0
 
   local pendingDescription = function(pending)
-    local name = pending.name
     local string = ''
 
     if type(pending.message) == 'string' then
@@ -175,7 +170,7 @@ return function(options)
     return nil, true
   end
 
-  handler.suiteStart = function(suite, count, total, randomseed)
+  handler.suiteStart = function(_suite, count, total, randomseed)
     if total > 1 then
       io.write(repeatSuiteString:format(count, total))
     end
@@ -196,7 +191,7 @@ return function(options)
     end
   end
 
-  handler.suiteEnd = function(suite, count, total)
+  handler.suiteEnd = function(suite, _count, _total)
     local elapsedTime_ms = getElapsedTime(suite)
     local tests = (testCount == 1 and 'test' or 'tests')
     local files = (fileCount == 1 and 'file' or 'files')
@@ -225,14 +220,14 @@ return function(options)
     return nil, true
   end
 
-  handler.testStart = function(element, parent)
+  handler.testStart = function(element, _parent)
     io.write(runString:format(handler.getFullName(element)))
     io.flush()
 
     return nil, true
   end
 
-  handler.testEnd = function(element, parent, status, debug)
+  handler.testEnd = function(element, _parent, status, _debug)
     local elapsedTime_ms = getElapsedTime(element)
     local string
 
@@ -263,7 +258,7 @@ return function(options)
     return nil, true
   end
 
-  handler.testFailure = function(element, parent, message, debug)
+  handler.testFailure = function(_element, _parent, _message, _debug)
     io.write(failureString)
     io.flush()
 
@@ -272,7 +267,7 @@ return function(options)
     return nil, true
   end
 
-  handler.testError = function(element, parent, message, debug)
+  handler.testError = function(_element, _parent, _message, _debug)
     io.write(errorString)
     io.flush()
 
@@ -281,7 +276,7 @@ return function(options)
     return nil, true
   end
 
-  handler.error = function(element, parent, message, debug)
+  handler.error = function(element, _parent, _message, _debug)
     if element.descriptor ~= 'it' then
       io.write(failureDescription(handler.errors[#handler.errors]))
       io.flush()