diff --git a/src/vm.c b/src/vm.c
index 5d2e04383..c32fb0c0a 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -238,6 +238,7 @@ cipush(mrb_state *mrb)
   ci->pc = 0;
   ci->err = 0;
   ci->proc = 0;
+  ci->acc = 0;
 
   return ci;
 }