diff --git a/python/map.c b/python/map.c
index 482e62f..31799a3 100644
--- a/python/map.c
+++ b/python/map.c
@@ -159,6 +159,7 @@
     case kUpb_MapInsertStatus_OutOfMemory:
       return false;
   }
+  return false;  // Unreachable, silence compiler warning.
 }
 
 int PyUpb_MapContainer_AssignSubscript(PyObject* _self, PyObject* key,