diff --git a/packages/angular/build/src/builders/dev-server/tests/behavior/build-errors_spec.ts b/packages/angular/build/src/builders/dev-server/tests/behavior/build-errors_spec.ts
index 424c520eab2d..9608e0dc976e 100644
--- a/packages/angular/build/src/builders/dev-server/tests/behavior/build-errors_spec.ts
+++ b/packages/angular/build/src/builders/dev-server/tests/behavior/build-errors_spec.ts
@@ -38,8 +38,8 @@ describeServeBuilder(executeDevServer, DEV_SERVER_BUILDER_INFO, (harness, setupT
             expectNoLog(logs, 'Unexpected character "EOF"');
           },
         ],
-        { outputLogsOnFailure: false, timeout: 90_000 },
+        { outputLogsOnFailure: false },
       );
-    }, 120_000);
+    });
   });
 });
diff --git a/packages/angular/build/src/tools/esbuild/watcher.ts b/packages/angular/build/src/tools/esbuild/watcher.ts
index 9923f08fea7f..e30909fa6813 100644
--- a/packages/angular/build/src/tools/esbuild/watcher.ts
+++ b/packages/angular/build/src/tools/esbuild/watcher.ts
@@ -8,6 +8,7 @@
 
 import type * as ParcelWatcher from '@parcel/watcher';
 import type * as Chokidar from 'chokidar';
+import { once } from 'node:events';
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import picomatch from 'picomatch';
@@ -663,8 +664,15 @@ async function createChokidarWatcher(
     usePolling: !!options?.polling,
     interval: options?.interval,
   });
+
   const initTime = Date.now();
 
+  // Wait for the watcher to complete its initial filesystem scan before returning.
+  // With `ignoreInitial: true`, any file visited during the initial scan is treated as the initial baseline
+  // and will not emit 'add' or 'change' events. Awaiting 'ready' ensures that rapid file modifications
+  // made right after watcher setup (e.g. in rebuild tests) are not swallowed as initial files.
+  await once(watcher, 'ready');
+
   const handleEvent = (type: 'added' | 'modified' | 'removed', rawPath: string) => {
     const posixPath = toPosixPathNormalized(rawPath);
     const lookupKey = toLookupKey(posixPath, isCaseSensitive);