diff --git a/include/sxt/sxtkey.h b/include/sxt/sxtkey.h
index e338420..ee35a88 100644
--- a/include/sxt/sxtkey.h
+++ b/include/sxt/sxtkey.h
@@ -76,7 +76,7 @@ void sxt_key_free(sxtkey_t *);
 int sxt_key_generate(sxtkey_t *, int , int );
 
 /* key custom hash ops */
-int sxt_key_assign_hash(const sxtkey_t *, uint64_t);
+int sxt_key_assign_hash(sxtkey_t *, uint64_t);
 uint64_t sxt_key_hash(const sxtkey_t *);
 
 #endif /* __SXT_SXTKEY_H__ */