diff --git a/lib/middleware/cache/redis.js b/lib/middleware/cache/redis.js
index eb534abcab..1e9889d0f6 100644
--- a/lib/middleware/cache/redis.js
+++ b/lib/middleware/cache/redis.js
@@ -32,8 +32,10 @@ module.exports = {
             let [value, cacheTtl] = await redisClient.mget(key, cacheTtlKey);
             if (value && refresh) {
                 if (!cacheTtl) {
+                    // if cacheTtl is not set, that means the cache expire time is contentExpire
                     cacheTtl = config.cache.contentExpire;
-                    redisClient.set(cacheTtlKey, cacheTtl, 'EX', cacheTtl);
+                    // dont save cacheTtl to Redis, as it is the default value
+                    // redisClient.set(cacheTtlKey, cacheTtl, 'EX', cacheTtl);
                 } else {
                     redisClient.expire(cacheTtlKey, cacheTtl);
                 }
@@ -54,7 +56,10 @@ module.exports = {
             value = JSON.stringify(value);
         }
         if (key) {
-            redisClient.set(getCacheTtlKey(key), maxAge, 'EX', maxAge);
+            if (maxAge !== config.cache.contentExpire) {
+                // Only set cacheTtlKey if maxAge !== contentExpire
+                redisClient.set(getCacheTtlKey(key), maxAge, 'EX', maxAge);
+            }
             return redisClient.set(key, value, 'EX', maxAge); // setMode: https://redis.io/commands/set
         }
     },