diff --git a/core/includes/ajax.inc b/core/includes/ajax.inc
index c67e981..5fa4bed 100644
--- a/core/includes/ajax.inc
+++ b/core/includes/ajax.inc
@@ -315,6 +315,10 @@ function ajax_render($commands = array()) {
 function ajax_get_form() {
   $form_state = form_state_defaults();
 
+  if ($_SERVER['CONTENT_TYPE'] == 'application/vnd.drupal-ajax') {
+    parse_str(file_get_contents("php://input"), $_POST);
+  }
+
   $form_build_id = $_POST['form_build_id'];
 
   // Get the form from the cache.
diff --git a/core/misc/ajax.js b/core/misc/ajax.js
index 4a1e327..c9a3f98 100644
--- a/core/misc/ajax.js
+++ b/core/misc/ajax.js
@@ -208,6 +208,7 @@ Drupal.ajax = function (base, element, element_settings) {
       }
     },
     dataType: 'json',
+    contentType: 'application/vnd.drupal-ajax',
     type: 'POST'
   };