diff --git a/src/main/java/net/lamgc/cgj/cache/RedisCacheStore.java b/src/main/java/net/lamgc/cgj/cache/RedisCacheStore.java
index ac54527..dfd45f3 100644
--- a/src/main/java/net/lamgc/cgj/cache/RedisCacheStore.java
+++ b/src/main/java/net/lamgc/cgj/cache/RedisCacheStore.java
@@ -32,7 +32,11 @@ public abstract class RedisCacheStore<T> implements CacheStore<T> {
         if(password != null) {
             this.jedis.auth(password);
         }
-        keyPrefix = prefix.endsWith(".") ? prefix : prefix + ".";
+        if(prefix != null) {
+            keyPrefix = prefix.endsWith(".") ? prefix : prefix + ".";
+        } else {
+            keyPrefix = "";
+        }
     }
 
     public void connect() {
diff --git a/src/main/java/net/lamgc/cgj/cache/RedisPoolCacheStore.java b/src/main/java/net/lamgc/cgj/cache/RedisPoolCacheStore.java
index bde0715..131e208 100644
--- a/src/main/java/net/lamgc/cgj/cache/RedisPoolCacheStore.java
+++ b/src/main/java/net/lamgc/cgj/cache/RedisPoolCacheStore.java
@@ -23,7 +23,11 @@ public abstract class RedisPoolCacheStore<T> implements CacheStore<T> {
                 redisServerUri.getPort() <= 0 ? 6379 : redisServerUri.getPort(),
                 timeout <= 0 ? Protocol.DEFAULT_TIMEOUT : timeout, password);
         log = LoggerFactory.getLogger("RedisPoolCacheStore@" + Integer.toHexString(jedisPool.hashCode()));
-        this.keyPrefix = prefix.endsWith(".") ? prefix : prefix + ".";
+        if(prefix != null) {
+            keyPrefix = prefix.endsWith(".") ? prefix : prefix + ".";
+        } else {
+            keyPrefix = "";
+        }
     }
 
     @Override