diff --git a/phc2sys.c b/phc2sys.c
index 3f2a0f8..66e34d6 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -1428,6 +1428,7 @@ int main(int argc, char *argv[])
 		case 'i':
 			fprintf(stderr,
 				"'-i' has been deprecated. please use '-s' instead.\n");
+            /* fallthrough */
 		case 's':
 			src_name = strdup(optarg);
 			break;