1 files changed, 1 insertions, 0 deletions
diff --git a/src/kernel.c b/src/kernel.c
index 083309d3e..ce96b902a 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -306,6 +306,7 @@ init_copy(mrb_state *mrb, mrb_value dest, mrb_value obj)
       case MRB_TT_SCLASS:
       case MRB_TT_HASH:
       case MRB_TT_DATA:
+      case MRB_TT_MAIN:
         mrb_iv_copy(mrb, dest, obj);
         break;