diff --git a/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer.ts b/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer.ts
index b339fd9793..d737a27a56 100644
--- a/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer.ts
+++ b/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer.ts
@@ -16,7 +16,22 @@ import { getScrubFileTransformer } from '../transforms/scrub-file';
 const hasDecorators = /decorators/;
 const hasCtorParameters = /ctorParameters/;
 const hasTsHelpers = /var (__extends|__decorate|__metadata|__param) = /;
-const isAngularPackage = /(\\|\/)node_modules(\\|\/)@angular(\\|\/)/;
+const isAngularModuleFile = /\.es5\.js$/;
+const whitelistedAngularModules = [
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)animations(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)common(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)compiler(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)core(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)forms(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)http(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)platform-browser-dynamic(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)platform-browser(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)platform-webworker-dynamic(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)platform-webworker(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)router(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)upgrade(\\|\/)/,
+  /(\\|\/)node_modules(\\|\/)@angular(\\|\/)material(\\|\/)/,
+];
 
 export interface BuildOptimizerOptions {
   content?: string;
@@ -46,13 +61,15 @@ export function buildOptimizer(options: BuildOptimizerOptions): TransformJavascr
     getTransforms.push(getImportTslibTransformer);
   }
 
-  if (inputFilePath && isAngularPackage.test(inputFilePath)) {
-    // Order matters, getPrefixFunctionsTransformer needs to be called before
-    // getFoldFileTransformer.
+  if (inputFilePath
+    && isAngularModuleFile.test(inputFilePath)
+    && whitelistedAngularModules.some((re) => re.test(inputFilePath))
+  ) {
     getTransforms.push(
-      // getPrefixFunctionsTransformer is rather dangerous.
+      // getPrefixFunctionsTransformer is rather dangerous, apply only to known pure modules.
       // It will mark both `require()` calls and `console.log(stuff)` as pure.
-      // We only apply it to @angular/* packages, since we know they are safe.
+      // We only apply it to whitelisted modules, since we know they are safe.
+      // getPrefixFunctionsTransformer needs to be before getFoldFileTransformer.
       getPrefixFunctionsTransformer,
       getScrubFileTransformer,
       getFoldFileTransformer,
diff --git a/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer_spec.ts b/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer_spec.ts
index d8bb7a64fe..64b9c0cc7c 100644
--- a/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer_spec.ts
+++ b/packages/angular_devkit/build_optimizer/src/build-optimizer/build-optimizer_spec.ts
@@ -40,7 +40,7 @@ describe('build-optimizer', () => {
       `;
       // tslint:enable:max-line-length
 
-      const inputFilePath = '/node_modules/@angular/some-lib';
+      const inputFilePath = '/node_modules/@angular/core/@angular/core.es5.js';
       const boOutput = buildOptimizer({ content: input, inputFilePath });
       expect(oneLine`${boOutput.content}`).toEqual(output);
       expect(boOutput.emitSkipped).toEqual(false);
@@ -83,6 +83,31 @@ describe('build-optimizer', () => {
     });
   });
 
+  describe('whitelisted modules', () => {
+    // This statement is considered pure by getPrefixFunctionsTransformer on whitelisted modules.
+    const input = 'console.log(42);';
+    const output = '/*@__PURE__*/ console.log(42);';
+
+    it('should process whitelisted modules', () => {
+      const inputFilePath = '/node_modules/@angular/core/@angular/core.es5.js';
+      const boOutput = buildOptimizer({ content: input, inputFilePath });
+      expect(boOutput.content).toContain(output);
+      expect(boOutput.emitSkipped).toEqual(false);
+    });
+
+    it('should not process non-whitelisted modules', () => {
+      const inputFilePath = '/node_modules/other-package/core.es5.js';
+      const boOutput = buildOptimizer({ content: input, inputFilePath });
+      expect(boOutput.emitSkipped).toEqual(true);
+    });
+
+    it('should not process non-whitelisted umd modules', () => {
+      const inputFilePath = '/node_modules/@angular/core/bundles/core.umd.js';
+      const boOutput = buildOptimizer({ content: input, inputFilePath });
+      expect(boOutput.emitSkipped).toEqual(true);
+    });
+  });
+
   describe('sourcemaps', () => {
     const transformableInput = oneLine`
       ${imports}