1 files changed, 1 insertions, 1 deletions
diff --git a/src/gc.c b/src/gc.c
index da6844fa5..ab50529f7 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -197,7 +197,7 @@ struct heap_page {
   struct heap_page *next;
   struct heap_page *free_next;
   struct heap_page *free_prev;
-  unsigned int old:1;
+  mrb_bool old:1;
   RVALUE objects[MRB_HEAP_PAGE_SIZE];
 };