diff --git a/src/vm.c b/src/vm.c
index 55bf6f5ee..d12297ec9 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -2011,6 +2011,7 @@ RETRY_TRY_BLOCK:
             }
             break;
           }
+          /* fallthrough */
         case OP_R_NORMAL:
         NORMAL_RETURN:
           if (ci == mrb->c->cibase) {