1 files changed, 1 insertions, 1 deletions
diff --git a/gc.c b/gc.c
index cbc95ddb26..7e86fb1141 100644
--- a/gc.c
+++ b/gc.c
@@ -547,7 +547,7 @@ rb_objspace_free(rb_objspace_t *objspace)
 #define CEILDIV(i, mod) (((i) + (mod) - 1)/(mod))
 
 #define HEAP_OBJ_LIMIT (unsigned int)((HEAP_SIZE - sizeof(struct heaps_header))/sizeof(struct RVALUE))
-#define HEAP_BITMAP_LIMIT CEILDIV(HEAP_OBJ_LIMIT, sizeof(uintptr_t)*8)
+#define HEAP_BITMAP_LIMIT CEILDIV(CEILDIV(HEAP_SIZE, sizeof(struct RVALUE)), sizeof(uintptr_t)*8)
 
 #define GET_HEAP_HEADER(x) (HEAP_HEADER(((uintptr_t)x) & ~(HEAP_ALIGN_MASK)))
 #define GET_HEAP_SLOT(x) (GET_HEAP_HEADER(x)->base)