diff --git a/misc/ahah.js b/misc/ahah.js
index e2a8659f53..f371d5aa0f 100644
--- a/misc/ahah.js
+++ b/misc/ahah.js
@@ -73,7 +73,7 @@ Drupal.ahah = function(base, element_settings) {
   // The 'this' variable will not persist inside of the options object.
   var ahah = this;
   var options = {
-    url: ahah.url,
+    url: Drupal.sanitizeAjaxUrl(ahah.url),
     data: ahah.button,
     beforeSubmit: function(form_values, element_settings, options) {
       return ahah.beforeSubmit(form_values, element_settings, options);
@@ -96,6 +96,7 @@ Drupal.ahah = function(base, element_settings) {
       }
     },
     dataType: 'json',
+    jsonp: false,
     type: 'POST'
   };
 
diff --git a/misc/autocomplete.js b/misc/autocomplete.js
index c5176727c4..7083d88ec6 100644
--- a/misc/autocomplete.js
+++ b/misc/autocomplete.js
@@ -278,8 +278,9 @@ Drupal.ACDB.prototype.search = function (searchString) {
     // Ajax GET request for autocompletion
     $.ajax({
       type: "GET",
-      url: db.uri +'/'+ Drupal.encodeURIComponent(searchString),
+      url: Drupal.sanitizeAjaxUrl(db.uri +'/'+ Drupal.encodeURIComponent(searchString)),
       dataType: 'json',
+      jsonp: false,
       success: function (matches) {
         if (typeof matches['status'] == 'undefined' || matches['status'] != 0) {
           db.cache[searchString] = matches;
diff --git a/misc/drupal.js b/misc/drupal.js
index a85b8f8579..b56892a6a8 100644
--- a/misc/drupal.js
+++ b/misc/drupal.js
@@ -270,6 +270,23 @@ Drupal.getSelection = function (element) {
   return { 'start': element.selectionStart, 'end': element.selectionEnd };
 };
 
+/**
+ * Sanitizes a URL for use with jQuery.ajax().
+ *
+ * @param url
+ *   The URL string to be sanitized.
+ *
+ * @return
+ *   The sanitized URL.
+ */
+Drupal.sanitizeAjaxUrl = function (url) {
+  var regex = /\=\?(&|$)/;
+  while (url.match(regex)) {
+    url = url.replace(regex, '');
+  }
+  return url;
+}
+
 /**
  * Build an error message from ahah response.
  */