diff --git a/gateway/platforms/whatsapp.py b/gateway/platforms/whatsapp.py
index a82417a601..75d839e10a 100644
--- a/gateway/platforms/whatsapp.py
+++ b/gateway/platforms/whatsapp.py
@@ -374,9 +374,16 @@ class WhatsAppAdapter(BasePlatformAdapter):
             logger.warning("[%s] Could not acquire session lock (non-fatal): %s", self.name, e)
 
         try:
-            # Auto-install npm dependencies if node_modules doesn't exist
+            # Auto-install npm dependencies if the bridge install is incomplete
             bridge_dir = bridge_path.parent
-            if not (bridge_dir / "node_modules").exists():
+            node_modules_dir = bridge_dir / "node_modules"
+            dependency_sentinels = [
+                node_modules_dir / "@whiskeysockets" / "baileys" / "package.json",
+                node_modules_dir / "express" / "package.json",
+                node_modules_dir / "qrcode-terminal" / "package.json",
+                node_modules_dir / "pino" / "package.json",
+            ]
+            if not node_modules_dir.exists() or any(not sentinel.exists() for sentinel in dependency_sentinels):
                 print(f"[{self.name}] Installing WhatsApp bridge dependencies...")
                 try:
                     install_result = subprocess.run(
diff --git a/hermes_cli/main.py b/hermes_cli/main.py
index 7de68d2cb4..6f711d45b4 100644
--- a/hermes_cli/main.py
+++ b/hermes_cli/main.py
@@ -1324,7 +1324,15 @@ def cmd_whatsapp(args):
         print(f"\n✗ Bridge script not found at {bridge_script}")
         return
 
-    if not (bridge_dir / "node_modules").exists():
+    node_modules_dir = bridge_dir / "node_modules"
+    dependency_sentinels = [
+        node_modules_dir / "@whiskeysockets" / "baileys" / "package.json",
+        node_modules_dir / "express" / "package.json",
+        node_modules_dir / "qrcode-terminal" / "package.json",
+        node_modules_dir / "pino" / "package.json",
+    ]
+
+    if not node_modules_dir.exists() or any(not sentinel.exists() for sentinel in dependency_sentinels):
         print("\n→ Installing WhatsApp bridge dependencies (this can take a few minutes)...")
         npm = shutil.which("npm")
         if not npm:
diff --git a/tests/gateway/test_whatsapp_connect.py b/tests/gateway/test_whatsapp_connect.py
index 29f7eee3af..f061fbd85d 100644
--- a/tests/gateway/test_whatsapp_connect.py
+++ b/tests/gateway/test_whatsapp_connect.py
@@ -214,6 +214,43 @@ class TestFileHandleClosedOnError:
 class TestConnectCleanup:
     """Verify failure paths release the scoped session lock."""
 
+    @pytest.mark.asyncio
+    async def test_releases_lock_when_baileys_package_is_missing(self):
+        adapter = _make_adapter()
+
+        def _path_exists(path_obj):
+            path_str = str(path_obj).replace("\\", "/")
+            if path_str.endswith("node_modules"):
+                return True
+            if path_str.endswith("@whiskeysockets/baileys/package.json"):
+                return False
+            return True
+
+        install_result = MagicMock(returncode=0, stderr="")
+        mock_proc = MagicMock()
+        mock_proc.poll.return_value = 1
+        mock_proc.returncode = 1
+        mock_fh = MagicMock()
+
+        with (
+            patch("gateway.platforms.whatsapp.check_whatsapp_requirements", return_value=True),
+            patch.object(Path, "exists", autospec=True, side_effect=_path_exists),
+            patch.object(Path, "mkdir", return_value=None),
+            patch("subprocess.run", return_value=install_result) as mock_run,
+            patch("subprocess.Popen", return_value=mock_proc),
+            patch("builtins.open", return_value=mock_fh),
+            patch("gateway.platforms.whatsapp.asyncio.sleep", new_callable=AsyncMock),
+            patch("gateway.platforms.whatsapp.asyncio.create_task"),
+            patch("gateway.status.acquire_scoped_lock", return_value=(True, None)),
+            patch("gateway.status.release_scoped_lock") as mock_release,
+        ):
+            result = await adapter.connect()
+
+        assert result is False
+        assert any(call.args and call.args[0][:2] == ["npm", "install"] for call in mock_run.call_args_list)
+        mock_release.assert_called_once_with("whatsapp-session", str(adapter._session_path))
+        assert adapter._platform_lock_identity is None
+
     @pytest.mark.asyncio
     async def test_releases_lock_when_npm_install_fails(self):
         adapter = _make_adapter()