diff --git a/includes/class.backend.php b/includes/class.backend.php
index 5948ac7e8..ca4b00bd7 100644
--- a/includes/class.backend.php
+++ b/includes/class.backend.php
@@ -311,6 +311,7 @@ public static function add_comment($task, $comment_text, $time = null)
 
 	if ($conf['general']['syntax_plugin'] != 'dokuwiki') {
 		$purifierconfig = HTMLPurifier_Config::createDefault();
+    $purifierconfig->set('Cache.SerializerPath', FS_CACHE_DIR);
 		$purifierconfig->set('CSS.AllowedProperties', array());
 		if ($fs->prefs['relnofollow']) {
 			$purifierconfig->set('HTML.Nofollow', true);
@@ -1087,6 +1088,7 @@ public static function create_task($args)
 	# dokuwiki syntax plugin filters on output
 	if ($conf['general']['syntax_plugin'] != 'dokuwiki' && isset($sql_args['detailed_desc'])) {
 		$purifierconfig = HTMLPurifier_Config::createDefault();
+    $purifierconfig->set('Cache.SerializerPath', FS_CACHE_DIR);
 		$purifierconfig->set('CSS.AllowedProperties', array());
 		if ($fs->prefs['relnofollow']) {
 			$purifierconfig->set('HTML.Nofollow', true);
diff --git a/includes/modify.inc.php b/includes/modify.inc.php
index 0b7d37b3c..c13e152b4 100644
--- a/includes/modify.inc.php
+++ b/includes/modify.inc.php
@@ -421,6 +421,7 @@ function resizeImage($file, $max_x, $max_y, $forcePng = false)
 	# dokuwiki syntax plugin filters on output
 	if ($conf['general']['syntax_plugin'] != 'dokuwiki') {
 		$purifierconfig = HTMLPurifier_Config::createDefault();
+    $purifierconfig->set('Cache.SerializerPath', FS_CACHE_DIR);
 		$purifierconfig->set('CSS.AllowedProperties', array());
 		if ($fs->prefs['relnofollow']) {
 			$purifierconfig->set('HTML.Nofollow', true);
@@ -2499,6 +2500,7 @@ function resizeImage($file, $max_x, $max_y, $forcePng = false)
 		# dokuwiki syntax plugin filters on output
 		if ($conf['general']['syntax_plugin'] != 'dokuwiki') {
 			$purifierconfig = HTMLPurifier_Config::createDefault();
+      $purifierconfig->set('Cache.SerializerPath', FS_CACHE_DIR);
 			$purifierconfig->set('CSS.AllowedProperties', array());
 			if ($fs->prefs['relnofollow']) {
 				$purifierconfig->set('HTML.Nofollow', true);