diff --git a/packages/compiler-cli/ngcc/src/host/esm2015_host.ts b/packages/compiler-cli/ngcc/src/host/esm2015_host.ts
index 31b88bded5..b951a6f597 100644
--- a/packages/compiler-cli/ngcc/src/host/esm2015_host.ts
+++ b/packages/compiler-cli/ngcc/src/host/esm2015_host.ts
@@ -318,20 +318,6 @@ export class Esm2015ReflectionHost extends TypeScriptReflectionHost implements N
     return null;
   }
 
-  hasBaseClass(clazz: ClassDeclaration): boolean {
-    const superHasBaseClass = super.hasBaseClass(clazz);
-    if (superHasBaseClass) {
-      return superHasBaseClass;
-    }
-
-    const innerClassDeclaration = getInnerClassDeclaration(clazz);
-    if (innerClassDeclaration === null) {
-      return false;
-    }
-
-    return super.hasBaseClass(innerClassDeclaration);
-  }
-
   getBaseClassExpression(clazz: ClassDeclaration): ts.Expression|null {
     // First try getting the base class from the "outer" declaration
     const superBaseClassIdentifier = super.getBaseClassExpression(clazz);
diff --git a/packages/compiler-cli/ngcc/src/host/esm5_host.ts b/packages/compiler-cli/ngcc/src/host/esm5_host.ts
index b93d37d968..fb2d7e0e01 100644
--- a/packages/compiler-cli/ngcc/src/host/esm5_host.ts
+++ b/packages/compiler-cli/ngcc/src/host/esm5_host.ts
@@ -33,28 +33,6 @@ import {NgccClassSymbol} from './ngcc_host';
  *
  */
 export class Esm5ReflectionHost extends Esm2015ReflectionHost {
-  /**
-   * Determines whether the given declaration, which should be a "class", has a base "class".
-   *
-   * In ES5 code, we need to determine if the IIFE wrapper takes a `_super` parameter .
-   *
-   * @param clazz a `ClassDeclaration` representing the class over which to reflect.
-   */
-  hasBaseClass(clazz: ClassDeclaration): boolean {
-    const classSymbol = this.getClassSymbol(clazz);
-    if (classSymbol === undefined) {
-      return false;
-    }
-
-    const iifeBody = getIifeBody(classSymbol.declaration.valueDeclaration);
-    if (!iifeBody) return false;
-
-    const iife = iifeBody.parent;
-    if (!iife || !ts.isFunctionExpression(iife)) return false;
-
-    return iife.parameters.length === 1 && isSuperIdentifier(iife.parameters[0].name);
-  }
-
   getBaseClassExpression(clazz: ClassDeclaration): ts.Expression|null {
     const classSymbol = this.getClassSymbol(clazz);
     if (classSymbol === undefined) {
diff --git a/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts b/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts
index e25a444938..b6df3545ad 100644
--- a/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts
+++ b/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts
@@ -128,9 +128,7 @@ export class TypeScriptReflectionHost implements ReflectionHost {
   }
 
   hasBaseClass(clazz: ClassDeclaration): boolean {
-    return (ts.isClassDeclaration(clazz) || ts.isClassExpression(clazz)) &&
-        clazz.heritageClauses !== undefined &&
-        clazz.heritageClauses.some(clause => clause.token === ts.SyntaxKind.ExtendsKeyword);
+    return this.getBaseClassExpression(clazz) !== null;
   }
 
   getBaseClassExpression(clazz: ClassDeclaration): ts.Expression|null {