diff --git a/modules/src/input/inp_pkg.body b/modules/src/input/inp_pkg.body
index 39d69e066..5fef47714 100644
--- a/modules/src/input/inp_pkg.body
+++ b/modules/src/input/inp_pkg.body
@@ -234,10 +234,10 @@ INP_mk_filename(dir, file, newname)
 	if (!dst) return 0;
 	*newname = dst;
 	if (*dir) {
-		while (*dst++ = *dir++);
-		*--dst = '/';
+		while (*dst++ = *dir++) ;
+		*(dst-1) = '/';
 	}
-	while (*++dst = *file++);
+	while (*dst++ = *file++);
 	return 1;
 }