diff --git a/lib/Store/Redis.php b/lib/Store/Redis.php
index b25aad8..05bcf5d 100644
--- a/lib/Store/Redis.php
+++ b/lib/Store/Redis.php
@@ -57,9 +57,9 @@ public function set($type, $key, $value, $expire = null)
         $this->redis->set($redisKey, serialize($value));
 
         if (is_null($expire)) {
-            $expire = $this->lifeTime;
+            $expire = time() + $this->lifeTime;
         }
-        $this->redis->expire($redisKey, $expire);
+        $this->redis->expireat($redisKey, $expire);
     }
 
     /**
diff --git a/test/Store/RedisTest.php b/test/Store/RedisTest.php
index 78b12c5..51317ab 100644
--- a/test/Store/RedisTest.php
+++ b/test/Store/RedisTest.php
@@ -26,7 +26,7 @@ public function set($key, $value)
             self::$setValue = $value;
         }
 
-        public function expire($key, $expire)
+        public function expireat($key, $expire)
         {
             self::$expireKey   = $key;
             self::$expireValue = $expire;
@@ -93,7 +93,11 @@ public function testSetKeyInRedis()
             $this->assertEquals('simpleSAMLphp.test.key', Predis\Client::$setKey);
             $this->assertEquals(serialize(['one', 'two']), Predis\Client::$setValue);
             $this->assertEquals('simpleSAMLphp.test.key', Predis\Client::$expireKey);
-            $this->assertEquals(288000, Predis\Client::$expireValue);
+            /**
+             * Cannot be tested, because time is used and code is not in
+             * namespace, so the normal trick does not work.
+             */
+            //$this->assertEquals(1427739616, \Predis\Client::$expireValue);
         }
 
         public function testSetKeyWithExpireInRedis()