1 files changed, 1 insertions, 0 deletions
diff --git a/eval.c b/eval.c
index d4f9cb8b38..25a15b3c30 100644
--- a/eval.c
+++ b/eval.c
@@ -8374,6 +8374,7 @@ block_pass(self, node)
     old_block = ruby_block;
     _block = *data;
     _block.outer = ruby_block;
+    _block.uniq = block_unique++;
     ruby_block = &_block;
     PUSH_ITER(ITER_PRE);
     if (ruby_frame->iter == ITER_NOT)