diff --git a/src/standard.c b/src/standard.c
index 910e1c298..02a183bfe 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -1409,7 +1409,7 @@ int port_to_str(struct sockaddr_storage *addr, char *str, int size)
 	uint16_t port;
 
 
-	if (size < 5)
+	if (size < 6)
 		return 0;
 	*str = '\0';