diff --git a/vllm/distributed/device_communicators/flashinfer_all_reduce.py b/vllm/distributed/device_communicators/flashinfer_all_reduce.py
index 8d3e8170924..4e4635035cc 100644
--- a/vllm/distributed/device_communicators/flashinfer_all_reduce.py
+++ b/vllm/distributed/device_communicators/flashinfer_all_reduce.py
@@ -67,6 +67,12 @@ def _create_workspace(
             comm_backend=comm_backend,
             group=group,
         )
+        if backend == "mnnvl" and not getattr(workspace, "mc_ptr", 0):
+            workspace.destroy()
+            logger.warning_once(
+                "FlashInfer MNNVL multicast is unavailable on the current topology."
+            )
+            return None
     except Exception as e:
         if "multicast" in str(e).lower():
             logger.warning_once(