diff --git a/tools/mkimage.c b/tools/mkimage.c
index 02f88bb..0c6dba8 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -64,6 +64,7 @@ static int show_valid_options(enum ih_category category)
 			genimg_get_cat_name(category, item));
 	}
 	fprintf(stderr, "\n");
+	free(order);
 
 	return 0;
 }