--- a/apps/app_osplookup.c
+++ b/apps/app_osplookup.c
@@ -994,7 +994,7 @@ static void osp_convert_inout(
        unsigned int destsize)
 {
        struct in_addr inp;
-       char buffer[OSP_SIZE_NORSTR];
+       char buffer[OSP_SIZE_NORSTR - strlen("[]:")];
        char* port;
 
        if ((dest != NULL) && (destsize > 0)) {