diff --git a/vllm/utils/__init__.py b/vllm/utils/__init__.py
index 72857ee2abc77..40f41893abb6a 100644
--- a/vllm/utils/__init__.py
+++ b/vllm/utils/__init__.py
@@ -1640,15 +1640,19 @@ def weak_bind(bound_method: Callable[..., Any], ) -> Callable[..., None]:
     return weak_bound
 
 
-# From: https://stackoverflow.com/a/4104188/2749989
 def run_once(f: Callable[P, None]) -> Callable[P, None]:
 
     def wrapper(*args: P.args, **kwargs: P.kwargs) -> None:
-        if not wrapper.has_run:  # type: ignore[attr-defined]
-            wrapper.has_run = True  # type: ignore[attr-defined]
-            return f(*args, **kwargs)
+        if wrapper.has_run:  # type: ignore[attr-defined]
+            return
+
+        with wrapper.lock:  # type: ignore[attr-defined]
+            if not wrapper.has_run:  # type: ignore[attr-defined]
+                wrapper.has_run = True  # type: ignore[attr-defined]
+                return f(*args, **kwargs)
 
     wrapper.has_run = False  # type: ignore[attr-defined]
+    wrapper.lock = threading.Lock()  # type: ignore[attr-defined]
     return wrapper