diff --git a/packages/compiler-cli/src/ngtsc/routing/src/analyzer.ts b/packages/compiler-cli/src/ngtsc/routing/src/analyzer.ts
index 5757055788..4443affdd2 100644
--- a/packages/compiler-cli/src/ngtsc/routing/src/analyzer.ts
+++ b/packages/compiler-cli/src/ngtsc/routing/src/analyzer.ts
@@ -12,7 +12,7 @@ import {ModuleResolver} from '../../imports';
 import {PartialEvaluator} from '../../partial_evaluator';
 
 import {scanForRouteEntryPoints} from './lazy';
-import {RouterEntryPointManager} from './route';
+import {RouterEntryPointManager, entryPointKeyFor} from './route';
 
 export interface NgModuleRawRouteData {
   sourceFile: ts.SourceFile;
@@ -38,9 +38,9 @@ export class NgModuleRouteAnalyzer {
 
   add(sourceFile: ts.SourceFile, moduleName: string, imports: ts.Expression|null,
       exports: ts.Expression|null, providers: ts.Expression|null): void {
-    const key = `${sourceFile.fileName}#${moduleName}`;
+    const key = entryPointKeyFor(sourceFile.fileName, moduleName);
     if (this.modules.has(key)) {
-      throw new Error(`Double route analyzing ${key}`);
+      throw new Error(`Double route analyzing for '${key}'.`);
     }
     this.modules.set(
         key, {
diff --git a/packages/compiler-cli/src/ngtsc/routing/src/route.ts b/packages/compiler-cli/src/ngtsc/routing/src/route.ts
index 8218fe4eb2..8c8a5bb7af 100644
--- a/packages/compiler-cli/src/ngtsc/routing/src/route.ts
+++ b/packages/compiler-cli/src/ngtsc/routing/src/route.ts
@@ -47,11 +47,15 @@ export class RouterEntryPointManager {
   }
 
   fromNgModule(sf: ts.SourceFile, moduleName: string): RouterEntryPoint {
-    const absoluteFile = sf.fileName;
-    const key = `${absoluteFile}#${moduleName}`;
+    const key = entryPointKeyFor(sf.fileName, moduleName);
     if (!this.map.has(key)) {
-      this.map.set(key, new RouterEntryPointImpl(absoluteFile, moduleName));
+      this.map.set(key, new RouterEntryPointImpl(sf.fileName, moduleName));
     }
     return this.map.get(key) !;
   }
 }
+
+export function entryPointKeyFor(filePath: string, moduleName: string): string {
+  // Drop the extension to be compatible with how cli calls `listLazyRoutes(entryRoute)`.
+  return `${filePath.replace(/\.tsx?$/i, '')}#${moduleName}`;
+}