diff --git a/lib/WebpackOptionsApply.js b/lib/WebpackOptionsApply.js
index a46688150..995a580a5 100644
--- a/lib/WebpackOptionsApply.js
+++ b/lib/WebpackOptionsApply.js
@@ -237,33 +237,35 @@ class WebpackOptionsApply extends OptionsApply {
 			new ModuleInfoHeaderPlugin().apply(compiler);
 		}
 
-		if (options.devtool && options.devtool.includes("source-map")) {
-			const hidden = options.devtool.includes("hidden");
-			const inline = options.devtool.includes("inline");
-			const evalWrapped = options.devtool.includes("eval");
-			const cheap = options.devtool.includes("cheap");
-			const moduleMaps = options.devtool.includes("module");
-			const noSources = options.devtool.includes("nosources");
-			const Plugin = evalWrapped
-				? require("./EvalSourceMapDevToolPlugin")
-				: require("./SourceMapDevToolPlugin");
-			new Plugin({
-				filename: inline ? null : options.output.sourceMapFilename,
-				moduleFilenameTemplate: options.output.devtoolModuleFilenameTemplate,
-				fallbackModuleFilenameTemplate:
-					options.output.devtoolFallbackModuleFilenameTemplate,
-				append: hidden ? false : "\n//# source" + "MappingURL=[url]",
-				module: moduleMaps ? true : cheap ? false : true,
-				columns: cheap ? false : true,
-				noSources: noSources,
-				namespace: options.output.devtoolNamespace
-			}).apply(compiler);
-		} else if (options.devtool && options.devtool.includes("eval")) {
-			const EvalDevToolModulePlugin = require("./EvalDevToolModulePlugin");
-			new EvalDevToolModulePlugin({
-				moduleFilenameTemplate: options.output.devtoolModuleFilenameTemplate,
-				namespace: options.output.devtoolNamespace
-			}).apply(compiler);
+		if (options.devtool) {
+			if (options.devtool.includes("source-map")) {
+				const hidden = options.devtool.includes("hidden");
+				const inline = options.devtool.includes("inline");
+				const evalWrapped = options.devtool.includes("eval");
+				const cheap = options.devtool.includes("cheap");
+				const moduleMaps = options.devtool.includes("module");
+				const noSources = options.devtool.includes("nosources");
+				const Plugin = evalWrapped
+					? require("./EvalSourceMapDevToolPlugin")
+					: require("./SourceMapDevToolPlugin");
+				new Plugin({
+					filename: inline ? null : options.output.sourceMapFilename,
+					moduleFilenameTemplate: options.output.devtoolModuleFilenameTemplate,
+					fallbackModuleFilenameTemplate:
+						options.output.devtoolFallbackModuleFilenameTemplate,
+					append: hidden ? false : undefined,
+					module: moduleMaps ? true : cheap ? false : true,
+					columns: cheap ? false : true,
+					noSources: noSources,
+					namespace: options.output.devtoolNamespace
+				}).apply(compiler);
+			} else if (options.devtool.includes("eval")) {
+				const EvalDevToolModulePlugin = require("./EvalDevToolModulePlugin");
+				new EvalDevToolModulePlugin({
+					moduleFilenameTemplate: options.output.devtoolModuleFilenameTemplate,
+					namespace: options.output.devtoolNamespace
+				}).apply(compiler);
+			}
 		}
 
 		new JavascriptModulesPlugin().apply(compiler);