diff --git a/packages/angular_devkit/build_angular/src/utils/process-bundle.ts b/packages/angular_devkit/build_angular/src/utils/process-bundle.ts
index 5faecf6acde2..3017163e7ce4 100644
--- a/packages/angular_devkit/build_angular/src/utils/process-bundle.ts
+++ b/packages/angular_devkit/build_angular/src/utils/process-bundle.ts
@@ -139,7 +139,7 @@ export async function inlineLocales(options: InlineOptions) {
     ast = parseSync(options.code, {
       babelrc: false,
       configFile: false,
-      sourceType: 'script',
+      sourceType: 'unambiguous',
       filename: options.filename,
     });
   } catch (error) {