diff --git a/skill.c b/skill.c

index ab83a03..01b29cb 100644

--- a/skill.c

+++ b/skill.c

@@ -640,14 +640,14 @@ static void skillsnice_parse(int argc,

 		case NS_OPTION:

 			ns_pid = atoi(optarg);

 			if (ns_pid == 0) {

-				xwarnx(_("invalid pid number %i"), optarg);

+				xwarnx(_("invalid pid number %s"), optarg);

 				kill_usage(stderr);

 			}

 			if (ns_read(ns_pid, &ns_task)) {

 				xwarnx(_("error reading reference namespace "

 					 "information"));

 				kill_usage(stderr);

-			}	

+			}

 			break;

 		case NSLIST_OPTION: