diff --git a/VERSION b/VERSION
index 88b68c3d..dcaa5238 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.1.0.1357
+4.1.0.1358
diff --git a/core/core.js b/core/core.js
index 8118910d..1e7d2c0e 100644
--- a/core/core.js
+++ b/core/core.js
@@ -1964,19 +1964,8 @@ function wrs_mathmlToImgObject(creator, mathml, wirisProperties, language) {
         imgObject.setAttribute('data-custom-editor', mathmlSubstring);
     }
 
-    // Experimental settings.
+    // Performance enabled
     if (_wrs_conf_wirisPluginPerformance && (_wrs_conf_saveMode == 'xml' || _wrs_conf_saveMode == 'safeXml')) {
-        // Internet Explorer 6-11
-        // http://stackoverflow.com/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser
-        var isIE = /*@cc_on!@*/false || !!document.documentMode;
-        if (isIE) {
-            data['useragent'] = 'IE';
-            _wrs_conf_imageFormat = 'png';
-        }
-        else {
-            data['useragent'] = 'other browser';
-            _wrs_conf_imageFormat = 'svg';
-        }
 
         var result = JSON.parse(wrs_createShowImageSrc(mathml, data, language));
         if (result["status"] == 'warning') {
diff --git a/version.php b/version.php
index a5db93ea..c964da9f 100644
--- a/version.php
+++ b/version.php
@@ -25,9 +25,9 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2017030100;
-$plugin->release = '4.1.0.1357';
+$plugin->version   = 2017030700;
+$plugin->release = '4.1.0.1358';
 $plugin->requires  = 2014050800;
 $plugin->component = 'atto_wiris';
-$plugin->dependencies = array ('filter_wiris' => 2017030100);
+$plugin->dependencies = array ('filter_wiris' => 2017030700);
 $plugin->maturity = MATURITY_STABLE;