diff --git a/types/webpack/index.d.ts b/types/webpack/index.d.ts
index 8c1e148c8f..97ab0d1324 100644
--- a/types/webpack/index.d.ts
+++ b/types/webpack/index.d.ts
@@ -27,6 +27,7 @@
 
 /// <reference types="node" />
 
+import { Hash as CryptoHash } from 'crypto';
 import {
   Tapable,
   HookMap,
@@ -923,12 +924,44 @@ declare namespace webpack {
             toString(): string;
         }
 
+        type GroupOptions = string | { name?: string; };
+
         class ChunkGroup {
+            chunks: Chunk[];
+            childrenIterable: SortableSet<ChunkGroup>;
+            parentsIterable: SortableSet<ChunkGroup>;
+            insertChunk(chunk: Chunk, before: Chunk): boolean;
+            getNumberOfChildren(): number;
+            setModuleIndex(module: Module, index: number): void;
+            getModuleIndex(module: Module): number | undefined;
+            setModuleIndex2(module: Module, index: number): void;
+            getModuleIndex2(module: Module): number | undefined;
+            addChild(chunk: ChunkGroup): boolean;
+            removeChild(chunk: ChunkGroup): boolean;
+            setParents(newParents: Iterable<ChunkGroup>): void;
         }
 
         class ChunkHash {
         }
 
+        interface SourcePosition {
+            line: number;
+            column?: number;
+        }
+
+        interface RealDependencyLocation {
+            start: SourcePosition;
+            end?: SourcePosition;
+            index?: number;
+        }
+
+        interface SynteticDependencyLocation {
+            name: string;
+            index?: number;
+        }
+
+        type DependencyLocation = SynteticDependencyLocation | RealDependencyLocation;
+
         class Dependency {
             constructor();
             getResourceIdentifier(): any;
@@ -1123,6 +1156,8 @@ declare namespace webpack {
             requireExtensions: SyncWaterfallHook<string, Chunk, string>;
             requireEnsure: SyncWaterfallHook<string, Chunk, string>;
             localVars: SyncWaterfallHook<string, Chunk, string>;
+            afterStartup: SyncWaterfallHook<string, Chunk, string>;
+            hashForChunk: SyncHook<CryptoHash, Chunk>;
           };
           outputOptions: Output;
           requireFn: string;
@@ -1201,6 +1236,8 @@ declare namespace webpack {
             missingDependencies: SortableSet<string>;
             hash?: string;
             getStats(): Stats;
+            addChunkInGroup(groupOptions: GroupOptions): ChunkGroup;
+            addChunkInGroup(groupOptions: GroupOptions, module: Module, loc: DependencyLocation, request: string): ChunkGroup;
             addModule(module: CompilationModule, cacheGroup: any): any;
             // tslint:disable-next-line:ban-types
             addEntry(context: any, entry: any, name: any, callback: Function): void;
diff --git a/types/webpack/test/index.ts b/types/webpack/test/index.ts
index 1ad44c9c7e..4e17f50c26 100644
--- a/types/webpack/test/index.ts
+++ b/types/webpack/test/index.ts
@@ -315,6 +315,18 @@ configuration = {
         mainTemplate.hooks.localVars.tap('SomePlugin', resource => {
           return resource.trimLeft();
         });
+        mainTemplate.hooks.afterStartup.tap('SomePlugin', (resource, chunk) => {
+            if (chunk.name) {
+                return `/* In named chunk: ${chunk.name} */ ${resource};`;
+            } else {
+                return resource;
+            }
+        });
+        mainTemplate.hooks.hashForChunk.tap('SomePlugin', (hash, chunk) => {
+            if (chunk.name) {
+                hash.update(chunk.name);
+            }
+        });
         if (mainTemplate.hooks.jsonpScript == null) {
           return;
         }
@@ -929,6 +941,45 @@ class DefinePlugin extends webpack.Plugin {
     }
 }
 
+class ChunkGroupTestPlugin extends webpack.Plugin {
+    apply(compiler: webpack.Compiler) {
+        compiler.hooks.compilation.tap("ChunkGroupTestPlugin", compilation  => {
+            const namedChunkGroupA = compilation.addChunkInGroup('vendors-a');
+            const namedChunkGroupB = compilation.addChunkInGroup({ name: 'vendors-b' });
+            const unnamedChunkGroup = compilation.addChunkInGroup({});
+            if (namedChunkGroupA.getNumberOfChildren() > 0) {
+                for (const chunk of namedChunkGroupA.chunks) {}
+            }
+            Array.from(namedChunkGroupA.childrenIterable).forEach(childGroup => {
+                namedChunkGroupA.removeChild(childGroup);
+                namedChunkGroupA.addChild(childGroup);
+            });
+            Array.from(namedChunkGroupA.parentsIterable).forEach(parentGroup => {});
+            namedChunkGroupA.setParents([namedChunkGroupB]);
+            namedChunkGroupA.setParents(new Set([unnamedChunkGroup]));
+            compilation.hooks.optimizeModules.tap("ChunkGroupTestPlugin", modules => {
+                for (const module of modules) {
+                    const group = compilation.addChunkInGroup('module', module, { start: { line: 0 } }, 'module.js');
+                    if (module.index) {
+                        group.setModuleIndex(module, module.index);
+                    }
+                    if (module.index2) {
+                        group.setModuleIndex2(module, module.index2);
+                    }
+                    console.log(group.getModuleIndex(module), group.getModuleIndex2(module));
+                    break;
+                }
+            });
+            compilation.hooks.optimizeChunks.tap("ChunkGroupTestPlugin", chunks => {
+                const firstChunk = chunks[0];
+                for (const groupChunk of namedChunkGroupA.chunks) {
+                    namedChunkGroupA.insertChunk(firstChunk, groupChunk);
+                }
+            });
+        });
+    }
+}
+
 configuration = {
     module: {
         rules: [