diff --git a/src/cluster/redis_slot.cc b/src/cluster/redis_slot.cc
index 627877895ed..3843eb0faf1 100644
--- a/src/cluster/redis_slot.cc
+++ b/src/cluster/redis_slot.cc
@@ -47,10 +47,9 @@ static const uint16_t crc16tab[256] = {
     0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74,
     0x2e93, 0x3eb2, 0x0ed1, 0x1ef0};
 
-uint16_t Crc16(const char *buf, int len) {
-  int i = 0;
+uint16_t Crc16(const char *buf, size_t len) {
   uint16_t crc = 0;
-  for (i = 0; i < len; i++) crc = (crc << 8) ^ crc16tab[((crc >> 8) ^ *buf++) & 0x00FF];
+  for (size_t i = 0; i < len; i++) crc = (crc << 8) ^ crc16tab[((crc >> 8) ^ *buf++) & 0x00FF];
   return crc;
 }
 
@@ -60,8 +59,8 @@ uint16_t GetSlotIdFromKey(const std::string &key) {
     tag = key;
   }
 
-  auto crc = Crc16(tag.data(), static_cast<int>(tag.size()));
-  return static_cast<int>(crc & HASH_SLOTS_MASK);
+  auto crc = Crc16(tag.data(), tag.size());
+  return crc & HASH_SLOTS_MASK;
 }
 
 std::string GetTagFromKey(const std::string &key) {
diff --git a/src/cluster/redis_slot.h b/src/cluster/redis_slot.h
index 5e55d124a4b..63c98d2e37e 100644
--- a/src/cluster/redis_slot.h
+++ b/src/cluster/redis_slot.h
@@ -26,6 +26,6 @@ constexpr const uint16_t HASH_SLOTS_MASK = 0x3fff;
 constexpr const uint16_t HASH_SLOTS_SIZE = HASH_SLOTS_MASK + 1;  // 16384
 constexpr const uint16_t HASH_SLOTS_MAX_ITERATIONS = 50;
 
-uint16_t Crc16(const char *buf, int len);
+uint16_t Crc16(const char *buf, size_t len);
 uint16_t GetSlotIdFromKey(const std::string &key);
 std::string GetTagFromKey(const std::string &key);