diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index 19fbdc0..d5b1d3c 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -163,6 +163,10 @@ public function get($key)
 	{
 		$data = $this->_redis->hMGet($key, array('__ci_type', '__ci_value'));
 
+		if (! isset($data['__ci_type'], $data['__ci_value']) || $data['__ci_value'] === false) {
+			return null;
+		}
+
 		if ($value !== FALSE && $this->_redis->sIsMember('_ci_redis_serialized', $key))
 		{
 			return FALSE;
@@ -226,6 +230,10 @@ public function save($id, $data, $ttl = 60, $raw = FALSE)
 			$this->_redis->{static::$_sRemove_name}('_ci_redis_serialized', $id);
 		}
 
+		if ($ttl !== 0) {
+			$this->_redis->expireAt($id, time() + $ttl);
+		}
+
 		return TRUE;
 	}