diff --git a/packages/compiler-cli/src/ngtsc/core/src/host.ts b/packages/compiler-cli/src/ngtsc/core/src/host.ts
index b7f49060e6..24683b131b 100644
--- a/packages/compiler-cli/src/ngtsc/core/src/host.ts
+++ b/packages/compiler-cli/src/ngtsc/core/src/host.ts
@@ -15,7 +15,7 @@ import {FactoryGenerator, isShim, ShimAdapter, ShimReferenceTagger, SummaryGener
 import {FactoryTracker, PerFileShimGenerator, TopLevelShimGenerator} from '../../shims/api';
 import {TypeCheckShimGenerator} from '../../typecheck';
 import {normalizeSeparators} from '../../util/src/path';
-import {getRootDirs, isDtsPath, isNonDeclarationTsPath} from '../../util/src/typescript';
+import {getRootDirs, isNonDeclarationTsPath, RequiredDelegations} from '../../util/src/typescript';
 import {ExtendedTsCompilerHost, NgCompilerAdapter, NgCompilerOptions, UnifiedModulesHost} from '../api';
 
 // A persistent source of bugs in CompilerHost delegation has been the addition by TS of new,
@@ -23,15 +23,6 @@ import {ExtendedTsCompilerHost, NgCompilerAdapter, NgCompilerOptions, UnifiedMod
 // the delegating host doesn't implement or delegate them. This causes subtle runtime failures. No
 // more. This infrastructure ensures that failing to delegate a method is a compile-time error.
 
-/**
- * Represents the `ExtendedTsCompilerHost` interface, with a transformation applied that turns all
- * methods (even optional ones) into required fields (which may be `undefined`, if the method was
- * optional).
- */
-export type RequiredCompilerHostDelegations = {
-  [M in keyof Required<ExtendedTsCompilerHost>]: ExtendedTsCompilerHost[M];
-};
-
 /**
  * Delegates all methods of `ExtendedTsCompilerHost` to a delegate, with the exception of
  * `getSourceFile` and `fileExists` which are implemented in `NgCompilerHost`.
@@ -40,7 +31,7 @@ export type RequiredCompilerHostDelegations = {
  * generated for this class.
  */
 export class DelegatingCompilerHost implements
-    Omit<RequiredCompilerHostDelegations, 'getSourceFile'|'fileExists'> {
+    Omit<RequiredDelegations<ExtendedTsCompilerHost>, 'getSourceFile'|'fileExists'> {
   constructor(protected delegate: ExtendedTsCompilerHost) {}
 
   private delegateMethod<M extends keyof ExtendedTsCompilerHost>(name: M):
@@ -89,7 +80,7 @@ export class DelegatingCompilerHost implements
  * `ExtendedTsCompilerHost` methods whenever present.
  */
 export class NgCompilerHost extends DelegatingCompilerHost implements
-    RequiredCompilerHostDelegations, ExtendedTsCompilerHost, NgCompilerAdapter {
+    RequiredDelegations<ExtendedTsCompilerHost>, ExtendedTsCompilerHost, NgCompilerAdapter {
   readonly factoryTracker: FactoryTracker|null = null;
   readonly entryPoint: AbsoluteFsPath|null = null;
   readonly constructionDiagnostics: ts.Diagnostic[];
diff --git a/packages/compiler-cli/src/ngtsc/typecheck/src/host.ts b/packages/compiler-cli/src/ngtsc/typecheck/src/host.ts
index d7283890c1..41b6d9dfdc 100644
--- a/packages/compiler-cli/src/ngtsc/typecheck/src/host.ts
+++ b/packages/compiler-cli/src/ngtsc/typecheck/src/host.ts
@@ -9,15 +9,7 @@
 import * as ts from 'typescript';
 
 import {copyFileShimData, ShimReferenceTagger} from '../../shims';
-
-/**
- * Represents the `ts.CompilerHost` interface, with a transformation applied that turns all
- * methods (even optional ones) into required fields (which may be `undefined`, if the method was
- * optional).
- */
-export type RequiredCompilerHostDelegations = {
-  [M in keyof Required<ts.CompilerHost>]: ts.CompilerHost[M];
-};
+import {RequiredDelegations} from '../../util/src/typescript';
 
 /**
  * Delegates all methods of `ts.CompilerHost` to a delegate, with the exception of
@@ -27,7 +19,7 @@ export type RequiredCompilerHostDelegations = {
  * generated for this class.
  */
 export class DelegatingCompilerHost implements
-    Omit<RequiredCompilerHostDelegations, 'getSourceFile'|'fileExists'|'writeFile'> {
+    Omit<RequiredDelegations<ts.CompilerHost>, 'getSourceFile'|'fileExists'|'writeFile'> {
   constructor(protected delegate: ts.CompilerHost) {}
 
   private delegateMethod<M extends keyof ts.CompilerHost>(name: M): ts.CompilerHost[M] {
diff --git a/packages/compiler-cli/src/ngtsc/util/src/typescript.ts b/packages/compiler-cli/src/ngtsc/util/src/typescript.ts
index c7bf5eed6b..f8ca1fb619 100644
--- a/packages/compiler-cli/src/ngtsc/util/src/typescript.ts
+++ b/packages/compiler-cli/src/ngtsc/util/src/typescript.ts
@@ -149,3 +149,11 @@ export function isAssignment(node: ts.Node): node is ts.BinaryExpression {
  * Asserts that the keys `K` form a subset of the keys of `T`.
  */
 export type SubsetOfKeys<T, K extends keyof T> = K;
+
+/**
+ * Represents the type `T`, with a transformation applied that turns all methods (even optional
+ * ones) into required fields (which may be `undefined`, if the method was optional).
+ */
+export type RequiredDelegations<T> = {
+  [M in keyof Required<T>]: T[M];
+};