diff --git a/packages/compiler-cli/src/ngcc/src/packages/transformer.ts b/packages/compiler-cli/src/ngcc/src/packages/transformer.ts
index b799970903..53d2a18def 100644
--- a/packages/compiler-cli/src/ngcc/src/packages/transformer.ts
+++ b/packages/compiler-cli/src/ngcc/src/packages/transformer.ts
@@ -15,6 +15,7 @@ import {SwitchMarkerAnalyzer} from '../analysis/switch_marker_analyzer';
 import {Esm2015ReflectionHost} from '../host/esm2015_host';
 import {Esm5ReflectionHost} from '../host/esm5_host';
 import {NgccReflectionHost} from '../host/ngcc_host';
+import {Esm5Renderer} from '../rendering/esm5_renderer';
 import {EsmRenderer} from '../rendering/esm_renderer';
 import {FileInfo, Renderer} from '../rendering/renderer';
 
@@ -128,11 +129,13 @@ export class Transformer {
       rewriteCoreImportsTo: ts.SourceFile|null, transformDts: boolean): Renderer {
     switch (format) {
       case 'esm2015':
-      case 'esm5':
       case 'fesm2015':
-      case 'fesm5':
         return new EsmRenderer(
             host, isCore, rewriteCoreImportsTo, this.sourcePath, this.targetPath, transformDts);
+      case 'esm5':
+      case 'fesm5':
+        return new Esm5Renderer(
+            host, isCore, rewriteCoreImportsTo, this.sourcePath, this.targetPath, transformDts);
       default:
         throw new Error(`Renderer for "${format}" not yet implemented.`);
     }
diff --git a/packages/compiler-cli/src/ngcc/src/rendering/esm5_renderer.ts b/packages/compiler-cli/src/ngcc/src/rendering/esm5_renderer.ts
new file mode 100644
index 0000000000..3d8c70e396
--- /dev/null
+++ b/packages/compiler-cli/src/ngcc/src/rendering/esm5_renderer.ts
@@ -0,0 +1,44 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import * as ts from 'typescript';
+import MagicString from 'magic-string';
+import {NgccReflectionHost} from '../host/ngcc_host';
+import {CompiledClass} from '../analysis/decoration_analyzer';
+import {EsmRenderer} from './esm_renderer';
+
+export class Esm5Renderer extends EsmRenderer {
+  constructor(
+      protected host: NgccReflectionHost, protected isCore: boolean,
+      protected rewriteCoreImportsTo: ts.SourceFile|null, protected sourcePath: string,
+      protected targetPath: string, transformDts: boolean) {
+    super(host, isCore, rewriteCoreImportsTo, sourcePath, targetPath, transformDts);
+  }
+
+  /**
+   * Add the definitions to each decorated class
+   */
+  addDefinitions(output: MagicString, compiledClass: CompiledClass, definitions: string): void {
+    const classSymbol = this.host.getClassSymbol(compiledClass.declaration);
+    if (!classSymbol) {
+      throw new Error(
+          `Compiled class does not have a valid symbol: ${compiledClass.name} in ${compiledClass.declaration.getSourceFile().fileName}`);
+    }
+    const parent = classSymbol.valueDeclaration && classSymbol.valueDeclaration.parent;
+    if (!parent || !ts.isBlock(parent)) {
+      throw new Error(
+          `Compiled class declaration is not inside an IIFE: ${compiledClass.name} in ${compiledClass.declaration.getSourceFile().fileName}`);
+    }
+    const returnStatement = parent.statements.find(statement => ts.isReturnStatement(statement));
+    if (!returnStatement) {
+      throw new Error(
+          `Compiled class wrapper IIFE does not have a return statement: ${compiledClass.name} in ${compiledClass.declaration.getSourceFile().fileName}`);
+    }
+    const insertionPoint = returnStatement.getFullStart();
+    output.appendLeft(insertionPoint, '\n' + definitions);
+  }
+}
diff --git a/packages/compiler-cli/src/ngcc/test/rendering/esm5_renderer_spec.ts b/packages/compiler-cli/src/ngcc/test/rendering/esm5_renderer_spec.ts
index 20d7f8a9ec..3cad53c8fc 100644
--- a/packages/compiler-cli/src/ngcc/test/rendering/esm5_renderer_spec.ts
+++ b/packages/compiler-cli/src/ngcc/test/rendering/esm5_renderer_spec.ts
@@ -7,11 +7,11 @@
  */
 import * as ts from 'typescript';
 import MagicString from 'magic-string';
-import {makeProgram} from '../helpers/utils';
+import {makeProgram, getDeclaration} from '../helpers/utils';
 import {DecorationAnalyzer} from '../../src/analysis/decoration_analyzer';
 import {SwitchMarkerAnalyzer} from '../../src/analysis/switch_marker_analyzer';
 import {Esm5ReflectionHost} from '../../src/host/esm5_host';
-import {EsmRenderer} from '../../src/rendering/esm_renderer';
+import {Esm5Renderer} from '../../src/rendering/esm5_renderer';
 
 function setup(file: {name: string, contents: string}) {
   const program = makeProgram(file);
@@ -20,7 +20,7 @@ function setup(file: {name: string, contents: string}) {
   const decorationAnalyses =
       new DecorationAnalyzer(program.getTypeChecker(), host, [''], false).analyzeProgram(program);
   const switchMarkerAnalyses = new SwitchMarkerAnalyzer(host).analyzeProgram(program);
-  const renderer = new EsmRenderer(host, false, null, '', '', false);
+  const renderer = new Esm5Renderer(host, false, null, '', '', false);
   return {host, program, sourceFile, renderer, decorationAnalyses, switchMarkerAnalyses};
 }
 
@@ -35,6 +35,9 @@ var A = (function() {
     { type: Directive, args: [{ selector: '[a]' }] },
     { type: OtherA }
   ];
+  A.prototype.ngDoCheck = function() {
+    //
+  };
   return A;
 }());
 
@@ -55,6 +58,15 @@ var C = (function() {
   return C;
 }());
 
+function NoIife() {}
+
+var BadIife = (function() {
+  function BadIife() {}
+  BadIife.decorators = [
+    { type: Directive, args: [{ selector: '[c]' }] },
+  ];
+}());
+
 var compileNgModuleFactory = compileNgModuleFactory__PRE_R3__;
 var badlyFormattedVariable = __PRE_R3__badlyFormattedVariable;
 function compileNgModuleFactory__PRE_R3__(injector, options, moduleType) {
@@ -68,7 +80,7 @@ function compileNgModuleFactory__POST_R3__(injector, options, moduleType) {
   return Promise.resolve(new R3NgModuleFactory(moduleType));
 }
 // Some other content
-export {A, B, C};`
+export {A, B, C, NoIife, BadIife};`
 };
 
 const PROGRAM_DECORATE_HELPER = {
@@ -179,19 +191,52 @@ var A = (function() {`);
   });
 
   describe('addDefinitions', () => {
-    it('should insert the definitions directly after the class declaration', () => {
-      const {renderer, decorationAnalyses, sourceFile} = setup(PROGRAM);
-      const output = new MagicString(PROGRAM.contents);
-      const compiledClass =
-          decorationAnalyses.get(sourceFile) !.compiledClasses.find(c => c.name === 'A') !;
-      renderer.addDefinitions(output, compiledClass, 'SOME DEFINITION TEXT');
-      expect(output.toString()).toContain(`
-  function A() {}
+    it('should insert the definitions directly before the return statement of the class IIFE',
+       () => {
+         const {renderer, decorationAnalyses, sourceFile} = setup(PROGRAM);
+         const output = new MagicString(PROGRAM.contents);
+         const compiledClass =
+             decorationAnalyses.get(sourceFile) !.compiledClasses.find(c => c.name === 'A') !;
+         renderer.addDefinitions(output, compiledClass, 'SOME DEFINITION TEXT');
+         expect(output.toString()).toContain(`
+  A.prototype.ngDoCheck = function() {
+    //
+  };
 SOME DEFINITION TEXT
-  A.decorators = [
+  return A;
 `);
-    });
+       });
 
+    it('should error if the compiledClass is not valid', () => {
+      const {renderer, host, sourceFile, program} = setup(PROGRAM);
+      const output = new MagicString(PROGRAM.contents);
+
+      const badSymbolDeclaration =
+          getDeclaration(program, sourceFile.fileName, 'A', ts.isVariableDeclaration);
+      const badSymbol: any = {name: 'BadSymbol', declaration: badSymbolDeclaration};
+      const hostSpy = spyOn(host, 'getClassSymbol').and.returnValue(null);
+      expect(() => renderer.addDefinitions(output, badSymbol, 'SOME DEFINITION TEXT'))
+          .toThrowError('Compiled class does not have a valid symbol: BadSymbol in /some/file.js');
+
+
+      const noIifeDeclaration =
+          getDeclaration(program, sourceFile.fileName, 'NoIife', ts.isFunctionDeclaration);
+      const mockNoIifeClass: any = {declaration: noIifeDeclaration, name: 'NoIife'};
+      hostSpy.and.returnValue({valueDeclaration: noIifeDeclaration});
+      expect(() => renderer.addDefinitions(output, mockNoIifeClass, 'SOME DEFINITION TEXT'))
+          .toThrowError(
+              'Compiled class declaration is not inside an IIFE: NoIife in /some/file.js');
+
+      const badIifeWrapper: any =
+          getDeclaration(program, sourceFile.fileName, 'BadIife', ts.isVariableDeclaration);
+      const badIifeDeclaration =
+          badIifeWrapper.initializer.expression.expression.body.statements[0];
+      const mockBadIifeClass: any = {declaration: badIifeDeclaration, name: 'BadIife'};
+      hostSpy.and.returnValue({valueDeclaration: badIifeDeclaration});
+      expect(() => renderer.addDefinitions(output, mockBadIifeClass, 'SOME DEFINITION TEXT'))
+          .toThrowError(
+              'Compiled class wrapper IIFE does not have a return statement: BadIife in /some/file.js');
+    });
   });