diff --git a/lib/formslib.php b/lib/formslib.php
index 03bb5f0..a76929b 100644
--- a/lib/formslib.php
+++ b/lib/formslib.php
@@ -2348,6 +2348,14 @@ class MoodleQuickForm_Renderer extends HTML_QuickForm_Renderer_Tableless{
             $html = str_replace('{help}', '', $html);
 
         }
+        // Removing labels from buttons if not required for improving accessibility MDL-30892
+        if ($element->getType() == 'submit' &&
+                empty($element->_label) &&
+                !$required &&
+                !(method_exists($element, 'getHelpButton') && empty($element->_helpbutton)) &&
+                !(isset($this->_advancedElements[$element->getName()])||$element->getName() == 'mform_showadvanced')) {
+            $html = preg_replace('$<label>(.+?)</label>$ism', '', $html, 1);
+        }
         if (($this->_inGroup) and !empty($this->_groupElementTemplate)) {
             $this->_groupElementTemplate = $html;
         }