diff --git a/lib/SimpleSAML/Store/Redis.php b/lib/SimpleSAML/Store/Redis.php
index 2f568e3600544953edfd2c43384ffe1be654850e..d102b01fd5d955fa2f7a880ba32cc7c320412b7e 100644
--- a/lib/SimpleSAML/Store/Redis.php
+++ b/lib/SimpleSAML/Store/Redis.php
@@ -98,7 +98,8 @@ class Redis extends Store
         if ($expire === null) {
             $this->redis->set("{$type}.{$key}", $serialized);
         } else {
-            $this->redis->setex("{$type}.{$key}", $expire, $serialized);
+            // setex expire time is in seconds (not unix timestamp)
+            $this->redis->setex("{$type}.{$key}", $expire - time(), $serialized);
         }
     }