diff --git a/src/variable.c b/src/variable.c
index dc28a0aa5..74535a8a7 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -19,9 +19,7 @@ typedef struct iv_tbl {
   mrb_value *ptr;
 } iv_tbl;
 
-#define IV_EMPTY 0
-#define IV_DELETED (1UL<<31)
-#define IV_KEY_P(k) (((k)&~((uint32_t)IV_DELETED))!=0)
+
 
 /* Creates the instance variable table. */
 static iv_tbl*