diff --git a/plugins/DiskCache/DiskCachePlugin.php b/plugins/DiskCache/DiskCachePlugin.php
index 3d6a0115db..b7b6ce5494 100644
--- a/plugins/DiskCache/DiskCachePlugin.php
+++ b/plugins/DiskCache/DiskCachePlugin.php
@@ -1,56 +1,47 @@
 <?php
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GNU social is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+
 /**
- * StatusNet - the distributed open-source microblogging tool
- * Copyright (C) 2009, StatusNet, Inc.
- *
  * Plugin to implement cache interface with disk files
  *
- * PHP version 5
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
  * @category  Cache
- * @package   StatusNet
+ * @package   GNUsocial
  * @author    Evan Prodromou <evan@status.net>
  * @copyright 2009 StatusNet, Inc.
- * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
- * @link      http://status.net/
+ * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
  */
 
-if (!defined('STATUSNET')) {
-    // This check helps protect against security problems;
-    // your code file can't be executed directly from the web.
-    exit(1);
-}
+defined('GNUSOCIAL') || die();
 
 /**
  * A plugin to cache data on local disk
  *
  * @category  Cache
- * @package   StatusNet
+ * @package   GNUsocial
  * @author    Evan Prodromou <evan@status.net>
  * @copyright 2009 StatusNet, Inc.
- * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
- * @link      http://status.net/
+ * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
  */
 class DiskCachePlugin extends Plugin
 {
     const PLUGIN_VERSION = '2.0.0';
 
-    var $root = '/tmp';
+    public $root = '/tmp';
 
-    function keyToFilename($key)
+    public function keyToFilename($key)
     {
         return $this->root . '/' . str_replace(':', '/', $key);
     }
@@ -65,17 +56,27 @@ class DiskCachePlugin extends Plugin
      *
      * @return boolean hook success
      */
-    function onStartCacheGet(&$key, &$value)
+    public function onStartCacheGet(&$key, &$value)
     {
         $filename = $this->keyToFilename($key);
 
+        $data = false;
         if (file_exists($filename)) {
             $data = file_get_contents($filename);
-            if ($data !== false) {
-                $value = unserialize($data);
-            }
         }
 
+        if ($data === false) {
+            return true;
+        }
+
+        $ret = unserialize($data);
+
+        if ($ret === false && $data !== 'b:0;') {
+            common_log(LOG_ERR, 'DiskCache could not handle: ' . $data);
+            return true;
+        }
+
+        $value = $ret;
         return false;
     }
 
@@ -90,7 +91,7 @@ class DiskCachePlugin extends Plugin
      *
      * @return boolean hook success
      */
-    function onStartCacheSet(&$key, &$value, &$flag, &$expiry, &$success)
+    public function onStartCacheSet(&$key, &$value, &$flag, &$expiry, &$success)
     {
         $filename = $this->keyToFilename($key);
         $parent = dirname($filename);
@@ -147,7 +148,7 @@ class DiskCachePlugin extends Plugin
      *
      * @return boolean hook success
      */
-    function onStartCacheDelete(&$key, &$success)
+    public function onStartCacheDelete(&$key, &$success)
     {
         $filename = $this->keyToFilename($key);
 
diff --git a/plugins/RedisCache/RedisCachePlugin.php b/plugins/RedisCache/RedisCachePlugin.php
index 7ae7b3cffa..d544355426 100644
--- a/plugins/RedisCache/RedisCachePlugin.php
+++ b/plugins/RedisCache/RedisCachePlugin.php
@@ -15,7 +15,7 @@
 // along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
- * Plguin inplementing Redis based caching
+ * Plugin inplementing Redis based caching
  *
  * @category  Files
  * @package   GNUsocial
@@ -58,21 +58,28 @@ class RedisCachePlugin extends Plugin
     {
         try {
             $this->_ensureConn();
-            $ret = $this->client->get($key);
+            $data = $this->client->get($key);
         } catch (PredisException $e) {
             common_log(LOG_ERR, 'RedisCache encountered exception ' . get_class($e) . ': ' . $e->getMessage());
             return true;
         }
 
-        // Hit, overwrite "value" and return false
-        // to indicate we took care of this
-        if ($ret !== null) {
-            $value = unserialize($ret);
-            return false;
+        if (is_null($data)) {
+            // Miss, let GS do its thing
+            return true;
         }
 
-        // Miss, let GS do its thing
-        return true;
+        $ret = unserialize($data);
+
+        if ($ret === false && $data !== 'b:0;') {
+            common_log(LOG_ERR, 'RedisCache could not handle: ' . $data);
+            return true;
+        }
+
+        // Hit, overwrite "value" and return false
+        // to indicate we took care of this
+        $value = $ret;
+        return false;
     }
 
     public function onStartCacheSet($key, $value, $flag, $expiry, &$success)