diff --git a/grpkill.c b/grpkill.c
index 8fd974a..84b1764 100644
--- a/grpkill.c
+++ b/grpkill.c
@@ -20,6 +20,7 @@ int main(int argc, char * argv[]){
 	}
 	if (sscanf(argv[1], "%i", &targetpid) != 1) {
 		fprintf(stderr, "error - argv[1] not an integer\n");
+			INVALID
 		return 2;
 	}