diff --git a/packages/@ngtools/webpack/src/compiler_host.ts b/packages/@ngtools/webpack/src/compiler_host.ts
index df8cd1d221b9..546ce6f9909e 100644
--- a/packages/@ngtools/webpack/src/compiler_host.ts
+++ b/packages/@ngtools/webpack/src/compiler_host.ts
@@ -187,6 +187,7 @@ export class WebpackCompilerHost implements ts.CompilerHost {
   }
 
   invalidate(fileName: string): void {
+    fileName = this._resolve(fileName);
     if (fileName in this._files) {
       this._files[fileName] = null;
       this._changedFiles[fileName] = true;