diff --git a/webpack/index.d.ts b/webpack/index.d.ts
index 18ab5274ba..0eb787a9b0 100644
--- a/webpack/index.d.ts
+++ b/webpack/index.d.ts
@@ -783,10 +783,28 @@ declare namespace webpack {
 
     namespace optimize {
         class AggressiveMergingPlugin extends Plugin {
-            constructor(options?: {
-                minSize?: number;
-                maxSize?: number;
-            });
+            constructor(options?: AggressiveMergingPlugin.Options);
+        }
+
+        namespace AggressiveMergingPlugin {
+            interface Options {
+                /**
+                 * When options.moveToParents is set, moving to an entry chunk is more expensive.
+                 * Defaults to 10, which means moving to an entry chunk is ten times more expensive than moving to a
+                 * normal chunk.
+                 */
+                entryChunkMultiplicator?: number;
+                /**
+                 * A factor which defines the minimum required size reduction for chunk merging.
+                 * Defaults to 1.5 which means that the total size needs to be reduced by 50% for chunk merging.
+                 */
+                minSizeReduce?: number;
+                /**
+                 * When set, modules that are not in both merged chunks are moved to all parents of the chunk.
+                 * Defaults to false.
+                 */
+                moveToParents?: boolean;
+            }
         }
 
         class CommonsChunkPlugin extends Plugin {
diff --git a/webpack/webpack-tests.ts b/webpack/webpack-tests.ts
index 8ab05c1de4..483e175f38 100644
--- a/webpack/webpack-tests.ts
+++ b/webpack/webpack-tests.ts
@@ -1,6 +1,33 @@
-
 import * as webpack from 'webpack';
 
+const {
+    optimize,
+} = webpack;
+
+let plugins: webpack.Plugin[];
+
+/**
+ * Plugins
+ */
+
+/**
+ * optimize
+ */
+
+const {
+    AggressiveMergingPlugin,
+} = optimize;
+
+plugins = [
+    new AggressiveMergingPlugin(),
+    new AggressiveMergingPlugin({}),
+    new AggressiveMergingPlugin({
+        entryChunkMultiplicator: 10,
+        minSizeReduce: 1.5,
+        moveToParents: false,
+    }),
+];
+
 let configuration: webpack.Configuration;
 let rule: webpack.Rule;
 let plugin: webpack.Plugin;
@@ -236,7 +263,6 @@ declare const context: any;
 declare const request: any;
 declare const types: any;
 declare const banner: any;
-const plugins: webpack.Plugin[] = [];
 
 plugin = new webpack.NormalModuleReplacementPlugin(resourceRegExp, newResource);
 plugin = new webpack.ContextReplacementPlugin(
@@ -334,7 +360,6 @@ plugin = new CommonsChunkPlugin({
     // minChunks: 3,
     // (3 children must share the module before it's separated)
 });
-plugin = new webpack.optimize.AggressiveMergingPlugin(options);
 plugin = new webpack.DefinePlugin(definitions);
 plugin = new webpack.DefinePlugin({
     "VERSION": JSON.stringify("5fa3b9"),