diff --git a/lib/default.php b/lib/default.php
index c78803da97..0fa8ce1678 100644
--- a/lib/default.php
+++ b/lib/default.php
@@ -296,11 +296,15 @@ $default =
         array('handle' => false,   // whether to handle sessions ourselves
               'debug' => false,    // debugging output for sessions
               'gc_limit' => 1000), // max sessions to expire at a time
-        'htmlfilter' => array(  // purify HTML through HTMLPurifier
+        'htmlfilter' => [  // remove tags from user/remotely generated HTML if they are === true
             'img' => true,
             'video' => true,
             'audio' => true,
-        ),
+        ],
+        'htmlpurifier' => [ // configurable options for HTMLPurifier
+            'Cache.DefinitionImpl'  => 'Serializer',
+            'Cache.SerializerPath'  => implode(DIRECTORY_SEPARATOR, [sys_get_temp_dir(), 'gnusocial']),
+        ],
         'notice' =>
         array('contentlimit' => null,
               'allowprivate' => false,  // whether to allow users to "check the padlock" to publish notices available for their subscribers.
diff --git a/lib/util.php b/lib/util.php
index c175c6e9ae..5aeda6d750 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -600,6 +600,9 @@ function common_purify($html, array $args=array())
         $cfg->set('URI.Base', $args['URI.Base']);   // if null this is like unsetting it I presume
         $cfg->set('URI.MakeAbsolute', !is_null($args['URI.Base']));   // if we have a URI base, convert relative URLs to absolute ones.
     }
+    foreach (common_config('htmlpurifier') as $key=>$val) {
+        $cfg->set($key, $val);
+    }
 
     // Remove more elements than what the default filter removes, default in GNU social are remotely
     // linked resources such as img, video, audio