diff --git a/src/trio/_socket.py b/src/trio/_socket.py
index ce57aab9c..6f8950d99 100644
--- a/src/trio/_socket.py
+++ b/src/trio/_socket.py
@@ -169,7 +169,8 @@ def set_custom_socket_factory(
 # getaddrinfo and friends
 ################################################################
 
-_NUMERIC_ONLY = _stdlib_socket.AI_NUMERICHOST | _stdlib_socket.AI_NUMERICSERV
+_NUMERIC_ONLY = _stdlib_socket.AI_NUMERICHOST
+_NUMERIC_ONLY |= getattr(_stdlib_socket, "AI_NUMERICSERV", 0)
 
 
 # It would be possible to @overload the return value depending on Literal[AddressFamily.INET/6], but should probably be added in typeshed first