diff --git a/vllm/utils.py b/vllm/utils.py
index 41336b80e3a2..4f905e505dbe 100644
--- a/vllm/utils.py
+++ b/vllm/utils.py
@@ -2461,7 +2461,7 @@ def make_zmq_path(scheme: str, host: str, port: Optional[int] = None) -> str:
     Returns:
         A properly formatted ZMQ path string.
     """
-    if not port:
+    if port is None:
         return f"{scheme}://{host}"
     if is_valid_ipv6_address(host):
         return f"{scheme}://[{host}]:{port}"