diff --git a/packages/compiler-cli/src/ngtsc/shims/src/host.ts b/packages/compiler-cli/src/ngtsc/shims/src/host.ts
index 58a9d551b3..a945ec06b6 100644
--- a/packages/compiler-cli/src/ngtsc/shims/src/host.ts
+++ b/packages/compiler-cli/src/ngtsc/shims/src/host.ts
@@ -48,10 +48,9 @@ export class GeneratedShimsHostWrapper implements ts.CompilerHost {
       fileName: string, languageVersion: ts.ScriptTarget,
       onError?: ((message: string) => void)|undefined,
       shouldCreateNewSourceFile?: boolean|undefined): ts.SourceFile|undefined {
-    const canonical = this.getCanonicalFileName(fileName);
     for (let i = 0; i < this.shimGenerators.length; i++) {
       const generator = this.shimGenerators[i];
-      const originalFile = generator.getOriginalSourceOfShim(canonical);
+      const originalFile = generator.getOriginalSourceOfShim(fileName);
       if (originalFile !== null) {
         // This shim generator has recognized the filename being requested, and is now responsible
         // for generating its contents, based on the contents of the original file it has requested.