diff --git a/examples/source-map/README.md b/examples/source-map/README.md
index 9b47cd2fe19..e3e21023943 100644
--- a/examples/source-map/README.md
+++ b/examples/source-map/README.md
@@ -181,7 +181,7 @@ race = function(winner, ...runners) {
 ```javascript
 /*
  * ATTENTION: An "eval-source-map" devtool has been used.
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file with attached SourceMaps in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".
@@ -208,7 +208,7 @@ eval("// Taken from http://coffeescript.org/\n\n// Objects:\nvar math, race;\n\n
 ```javascript
 /*
  * ATTENTION: The "eval" devtool has been used (maybe by default in mode: "development").
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".
@@ -235,7 +235,7 @@ eval("// Taken from http://coffeescript.org/\n\n// Objects:\nvar math, race;\n\n
 ```javascript
 /*
  * ATTENTION: An "eval-source-map" devtool has been used.
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file with attached SourceMaps in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".
@@ -262,7 +262,7 @@ eval("// Taken from http://coffeescript.org/\n\n// Objects:\nvar math, race;\n\n
 ```javascript
 /*
  * ATTENTION: An "eval-source-map" devtool has been used.
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file with attached SourceMaps in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".
diff --git a/lib/EvalDevToolModulePlugin.js b/lib/EvalDevToolModulePlugin.js
index dd625f754c3..6bc025e85d0 100644
--- a/lib/EvalDevToolModulePlugin.js
+++ b/lib/EvalDevToolModulePlugin.js
@@ -17,7 +17,7 @@ const cache = new WeakMap();
 
 const devtoolWarning = new RawSource(`/*
  * ATTENTION: The "eval" devtool has been used (maybe by default in mode: "development").
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".
diff --git a/lib/EvalSourceMapDevToolPlugin.js b/lib/EvalSourceMapDevToolPlugin.js
index 865c7bc447c..b6d836b3fd4 100644
--- a/lib/EvalSourceMapDevToolPlugin.js
+++ b/lib/EvalSourceMapDevToolPlugin.js
@@ -23,7 +23,7 @@ const cache = new WeakMap();
 
 const devtoolWarning = new RawSource(`/*
  * ATTENTION: An "eval-source-map" devtool has been used.
- * This devtool is not neither made for production nor for readable output files.
+ * This devtool is neither made for production nor for readable output files.
  * It uses "eval()" calls to create a separate source file with attached SourceMaps in the browser devtools.
  * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
  * or disable the default devtool with "devtool: false".