diff --git a/packages/@ngtools/webpack/src/loader.spec.ts b/packages/@ngtools/webpack/src/loader.spec.ts
index 7e39c2c8224a..5514dd342f7f 100644
--- a/packages/@ngtools/webpack/src/loader.spec.ts
+++ b/packages/@ngtools/webpack/src/loader.spec.ts
@@ -11,16 +11,49 @@ describe('@ngtools/webpack', () => {
         host.writeFile('/file.ts', `
           export const obj = { moduleId: 123 };
           export const obj2 = { moduleId: 123, otherValue: 1 };
-          export const obj2 = { otherValue: 1, moduleId: 123 };
+          export const obj3 = { otherValue: 1, moduleId: 123 };
+        `, false);
+        host.writeFile('/file2.ts', `
+          @SomeDecorator({ moduleId: 123 }) class CLS {}
+          @SomeDecorator({ moduleId: 123, otherValue1: 1 }) class CLS2 {}
+          @SomeDecorator({ otherValue2: 2, moduleId: 123, otherValue3: 3 }) class CLS3 {}
+          @SomeDecorator({ otherValue4: 4, moduleId: 123 }) class CLS4 {}
         `, false);
 
-        const program = ts.createProgram(['/file.ts'], {}, host);
+        const program = ts.createProgram(['/file.ts', '/file2.ts'], {}, host);
 
         const refactor = new TypeScriptFileRefactor('/file.ts', host, program);
         removeModuleIdOnlyForTesting(refactor);
+        expect(refactor.sourceText).not.toMatch(/obj = \{\s+};/);
+        expect(refactor.sourceText).not.toMatch(/\{\s*otherValue: 1\s*};/);
+
+        const refactor2 = new TypeScriptFileRefactor('/file2.ts', host, program);
+        removeModuleIdOnlyForTesting(refactor2);
+        expect(refactor2.sourceText).toMatch(/\(\{\s+}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue1: 1\s*}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue2: 2\s*,\s*otherValue3: 3\s*}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue4: 4\s*}\)/);
+      });
 
-        expect(refactor.sourceText).toMatch(/obj = \{\s+};/);
-        expect(refactor.sourceText).toMatch(/obj2 = \{\s*otherValue: 1\s*};/);
+      it('should work without a root name', () => {
+        const host = new WebpackCompilerHost({}, '');
+        host.writeFile('/file.ts', `
+          import './file2.ts';
+        `, false);
+        host.writeFile('/file2.ts', `
+          @SomeDecorator({ moduleId: 123 }) class CLS {}
+          @SomeDecorator({ moduleId: 123, otherValue1: 1 }) class CLS2 {}
+          @SomeDecorator({ otherValue2: 2, moduleId: 123, otherValue3: 3 }) class CLS3 {}
+          @SomeDecorator({ otherValue4: 4, moduleId: 123 }) class CLS4 {}
+        `, false);
+
+        const program = ts.createProgram(['/file.ts'], {}, host);
+        const refactor = new TypeScriptFileRefactor('/file2.ts', host, program);
+        removeModuleIdOnlyForTesting(refactor);
+        expect(refactor.sourceText).toMatch(/\(\{\s+}\)/);
+        expect(refactor.sourceText).toMatch(/\(\{\s*otherValue1: 1\s*}\)/);
+        expect(refactor.sourceText).toMatch(/\(\{\s*otherValue2: 2\s*,\s*otherValue3: 3\s*}\)/);
+        expect(refactor.sourceText).toMatch(/\(\{\s*otherValue4: 4\s*}\)/);
       });
     });
   });
diff --git a/packages/@ngtools/webpack/src/loader.ts b/packages/@ngtools/webpack/src/loader.ts
index 57197dd905be..b297c8b18f38 100644
--- a/packages/@ngtools/webpack/src/loader.ts
+++ b/packages/@ngtools/webpack/src/loader.ts
@@ -241,7 +241,10 @@ export function removeModuleIdOnlyForTesting(refactor: TypeScriptFileRefactor) {
 function _removeModuleId(refactor: TypeScriptFileRefactor) {
   const sourceFile = refactor.sourceFile;
 
-  refactor.findAstNodes(sourceFile, ts.SyntaxKind.ObjectLiteralExpression, true)
+  refactor.findAstNodes(sourceFile, ts.SyntaxKind.Decorator, true)
+    .reduce((acc, node) => {
+      return acc.concat(refactor.findAstNodes(node, ts.SyntaxKind.ObjectLiteralExpression, true));
+    }, [])
     // Get all their property assignments.
     .filter((node: ts.ObjectLiteralExpression) => {
       return node.properties.some(prop => {
@@ -254,8 +257,9 @@ function _removeModuleId(refactor: TypeScriptFileRefactor) {
         return prop.kind == ts.SyntaxKind.PropertyAssignment
             && _getContentOfKeyLiteral(sourceFile, prop.name) == 'moduleId';
       })[0];
-      // get the trailing comma
-      const moduleIdCommaProp = moduleIdProp.parent.getChildAt(1).getChildren()[1];
+      // Get the trailing comma.
+      const moduleIdCommaProp = moduleIdProp.parent
+        ? moduleIdProp.parent.getChildAt(1).getChildren()[1] : null;
       refactor.removeNodes(moduleIdProp, moduleIdCommaProp);
     });
 }
diff --git a/packages/@ngtools/webpack/src/refactor.ts b/packages/@ngtools/webpack/src/refactor.ts
index 7b11da71d3a1..25c85f946415 100644
--- a/packages/@ngtools/webpack/src/refactor.ts
+++ b/packages/@ngtools/webpack/src/refactor.ts
@@ -45,9 +45,8 @@ export class TypeScriptFileRefactor {
       this._sourceFile = _program.getSourceFile(fileName);
     }
     if (!this._sourceFile) {
-      this._program = null;
       this._sourceFile = ts.createSourceFile(fileName, _host.readFile(fileName),
-        ts.ScriptTarget.Latest);
+        ts.ScriptTarget.Latest, true);
     }
     this._sourceText = this._sourceFile.getFullText(this._sourceFile);
     this._sourceString = new MagicString(this._sourceText);