diff --git a/src/namespace.c b/src/namespace.c
index f23da48f8..89a968e36 100644
--- a/src/namespace.c
+++ b/src/namespace.c
@@ -121,7 +121,8 @@ int my_socketat(const struct netns_entry *ns, int domain, int type, int protocol
 	sock = socket(domain, type, protocol);
 
 	if (default_namespace >= 0 && ns && setns(default_namespace, CLONE_NEWNET) == -1) {
-		close(sock);
+		if (sock >= 0)
+			close(sock);
 		return -1;
 	}
 	return sock;