diff --git a/setup.py b/setup.py
index a47b14ff..d534cec4 100644
--- a/setup.py
+++ b/setup.py
@@ -378,6 +378,7 @@ package_data = {
     "vllm": ["py.typed", "model_executor/layers/fused_moe/configs/*.json"]
 }
 if os.environ.get("VLLM_USE_PRECOMPILED"):
+    ext_modules = []
     package_data["vllm"].append("*.so")
 
 setup(