diff --git a/packages/compiler-cli/src/ngtsc/compiler_host.ts b/packages/compiler-cli/src/ngtsc/compiler_host.ts
index 9246385e81..f40725e236 100644
--- a/packages/compiler-cli/src/ngtsc/compiler_host.ts
+++ b/packages/compiler-cli/src/ngtsc/compiler_host.ts
@@ -36,14 +36,19 @@ export interface CompilerHost extends ts.CompilerHost {
 export class NgtscCompilerHost implements CompilerHost {
   constructor(private delegate: ts.CompilerHost) {
     if (delegate.resolveTypeReferenceDirectives) {
+      // Backward compatibility with TypeScript 2.9 and older since return
+      // type has changed from (ts.ResolvedTypeReferenceDirective | undefined)[]
+      // to ts.ResolvedTypeReferenceDirective[] in Typescript 3.0
+      type ts3ResolveTypeReferenceDirectives = (names: string[], containingFile: string) =>
+          ts.ResolvedTypeReferenceDirective[];
       this.resolveTypeReferenceDirectives = (names: string[], containingFile: string) =>
-          delegate.resolveTypeReferenceDirectives !(names, containingFile);
+          (delegate.resolveTypeReferenceDirectives as ts3ResolveTypeReferenceDirectives) !(
+              names, containingFile);
     }
   }
 
   resolveTypeReferenceDirectives?:
-      (names: string[],
-       containingFile: string) => (ts.ResolvedTypeReferenceDirective | undefined)[];
+      (names: string[], containingFile: string) => ts.ResolvedTypeReferenceDirective[];
 
   getSourceFile(
       fileName: string, languageVersion: ts.ScriptTarget,
diff --git a/packages/compiler-cli/src/transformers/compiler_host.ts b/packages/compiler-cli/src/transformers/compiler_host.ts
index f286f0c4b6..ec9494b9db 100644
--- a/packages/compiler-cli/src/transformers/compiler_host.ts
+++ b/packages/compiler-cli/src/transformers/compiler_host.ts
@@ -83,8 +83,7 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter implements ts.CompilerHos
   // TODO(issue/24571): remove '!'.
   getDirectories !: (path: string) => string[];
   resolveTypeReferenceDirectives?:
-      (names: string[],
-       containingFile: string) => (ts.ResolvedTypeReferenceDirective | undefined)[];
+      (names: string[], containingFile: string) => ts.ResolvedTypeReferenceDirective[];
   directoryExists?: (directoryName: string) => boolean;
 
   constructor(
@@ -110,8 +109,14 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter implements ts.CompilerHos
       this.getDefaultLibLocation = () => context.getDefaultLibLocation !();
     }
     if (context.resolveTypeReferenceDirectives) {
+      // Backward compatibility with TypeScript 2.9 and older since return
+      // type has changed from (ts.ResolvedTypeReferenceDirective | undefined)[]
+      // to ts.ResolvedTypeReferenceDirective[] in Typescript 3.0
+      type ts3ResolveTypeReferenceDirectives = (names: string[], containingFile: string) =>
+          ts.ResolvedTypeReferenceDirective[];
       this.resolveTypeReferenceDirectives = (names: string[], containingFile: string) =>
-          context.resolveTypeReferenceDirectives !(names, containingFile);
+          (context.resolveTypeReferenceDirectives as ts3ResolveTypeReferenceDirectives) !(
+              names, containingFile);
     }
     if (context.trace) {
       this.trace = s => context.trace !(s);