diff --git a/inc/auth.php b/inc/auth.php
index e139db4fa5e927b4d4a13fca5c85c4f25b1ba321..d5af6436a581e4031431f3a09cc45b4d9f076283 100644
--- a/inc/auth.php
+++ b/inc/auth.php
@@ -143,7 +143,7 @@ function auth_browseruid(){
  * Creates a random key to encrypt the password in cookies
  *
  * This function tries to read the password for encrypting
- * cookies from $conf['datadir'].'/.cache/.htcookiesalt'
+ * cookies from $conf['datadir'].'/_cache/_htcookiesalt'
  * if no such file is found a random key is created and
  * and stored in this file.
  *
@@ -153,7 +153,7 @@ function auth_browseruid(){
  */
 function auth_cookiesalt(){
   global $conf;
-  $file = $conf['datadir'].'/.cache/.htcookiesalt';
+  $file = $conf['datadir'].'/_cache/_htcookiesalt';
   $salt = io_readFile($file);
   if(empty($salt)){
     $salt = uniqid(rand(),true);
diff --git a/inc/common.php b/inc/common.php
index 251fbcdc3bb2db60323c62678ba572051687ba80..62794d83427916c01b26f1e3f71d90985608ed91 100644
--- a/inc/common.php
+++ b/inc/common.php
@@ -712,7 +712,7 @@ function saveWikiText($id,$text,$summary){
   
   //purge cache on add by updating the purgefile
   if($conf['purgeonadd'] && (!$old || $del)){
-    io_saveFile($conf['datadir'].'/.cache/purgefile',time());
+    io_saveFile($conf['datadir'].'/_cache/purgefile',time());
   }
 }
 
diff --git a/inc/format.php b/inc/format.php
index 77d2e0d54d8ab0b1888d6e8559adcb158c47771f..2dbb43a97252e42276b0775e9c70e202865c23a0 100644
--- a/inc/format.php
+++ b/inc/format.php
@@ -486,13 +486,13 @@ function img_cache(&$csrc,&$src,&$w,&$h,$cachemode){
 
   //download external images if allowed
   if($isurl && $isimg && $cachemode != 'nocache'){
-    $cache = $conf['mediadir']."/.cache/$md5.$ext";
+    $cache = $conf['mediadir']."/_cache/$md5.$ext";
     if ( ($cachemode == 'recache' && download($src,$cache)) ||
          @file_exists($cache) || download($src,$cache)){
-      $f['full']['web'] = $conf['mediaweb']."/.cache/$md5.$ext";
-      $f['resz']['web'] = $conf['mediaweb']."/.cache/$md5.$ext";
-      $f['full']['fs']  = $conf['mediadir']."/.cache/$md5.$ext";
-      $f['resz']['fs']  = $conf['mediadir']."/.cache/$md5.$ext";
+      $f['full']['web'] = $conf['mediaweb']."/_cache/$md5.$ext";
+      $f['resz']['web'] = $conf['mediaweb']."/_cache/$md5.$ext";
+      $f['full']['fs']  = $conf['mediadir']."/_cache/$md5.$ext";
+      $f['resz']['fs']  = $conf['mediadir']."/_cache/$md5.$ext";
       $isurl = false;
     }
   }
@@ -505,15 +505,15 @@ function img_cache(&$csrc,&$src,&$w,&$h,$cachemode){
       if(!$h){
         $h = round(($w * $info[1]) / $info[0]);
       }
-      $cache = $conf['mediadir'].'/.cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
+      $cache = $conf['mediadir'].'/_cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
       //delete outdated cachefile
       if(@file_exists($cache) && (filemtime($cache)<filemtime($f['full']['fs']))){
         unlink($cache);
       }
       //check if a resized cachecopy exists else create one
       if(@file_exists($cache) || img_resize($ext,$f['full']['fs'],$info[0],$info[1],$cache,$w,$h)){
-        $f['resz']['web'] = $conf['mediaweb'].'/.cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
-        $f['resz']['fs']  = $conf['mediadir'].'/.cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
+        $f['resz']['web'] = $conf['mediaweb'].'/_cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
+        $f['resz']['fs']  = $conf['mediadir'].'/_cache/'.$md5.'.'.$w.'x'.$h.'.'.$ext;
       }
     }else{
       //if no new size was given just return the img size
diff --git a/inc/io.php b/inc/io.php
index ceb747ed91819988d982574b608de15b3fecb58f..2d5e8e585a9fea4969a49eadd628141c396e91db 100644
--- a/inc/io.php
+++ b/inc/io.php
@@ -21,9 +21,9 @@ function io_cacheParse($file){
   global $CACHEGROUP;
   global $parser; //we read parser options
   $parsed = '';
-  $cache  = $conf['datadir'].'/.cache/';
+  $cache  = $conf['datadir'].'/_cache/';
   $cache .= md5($file.$_SERVER['HTTP_HOST'].$_SERVER['SERVER_PORT'].$CACHEGROUP);
-  $purge  = $conf['datadir'].'/.cache/purgefile';
+  $purge  = $conf['datadir'].'/_cache/purgefile';
 
   // check if cache can be used
   $cachetime = @filemtime($cache);