diff --git a/vllm/model_executor/models/registry.py b/vllm/model_executor/models/registry.py
index 81623def..2a6e2c92 100644
--- a/vllm/model_executor/models/registry.py
+++ b/vllm/model_executor/models/registry.py
@@ -521,6 +521,7 @@ def _run_in_subprocess(fn: Callable[[], _T]) -> _T:
         # contains relative imports
         returned = subprocess.run(_SUBPROCESS_COMMAND,
                                   input=input_bytes,
+                                  env={'PYTHONPATH': ':'.join(sys.path)},
                                   capture_output=True)
 
         # check if the subprocess is successful