diff --git a/js/ajax.js b/js/ajax.js
index af795a57..d2319f39 100644
--- a/js/ajax.js
+++ b/js/ajax.js
@@ -18,7 +18,13 @@ $(window).ready(function() {
 
     // Enable submit button if disabled (cache problem)
     $('input[type="submit"]').removeAttr('disabled');
-    
+
+    // In the captcha is present, halt if it does not have a response..
+    if (captcha_renderer && postCaptchaId && !captcha_renderer.hasResponse(postCaptchaId)) {
+        captcha_renderer.execute(postCaptchaId);
+        return false;
+    }
+
     var setup_form = function($form) {
         $form.submit(function() {
             if (do_not_ajax)
@@ -27,7 +33,7 @@ $(window).ready(function() {
             var submit_txt = $(this).find('input[type="submit"]').val();
             if (window.FormData === undefined)
                 return true;
-            
+
             var formData = new FormData(this);
             formData.append('json_response', '1');
             formData.append('post', submit_txt);
@@ -94,11 +100,11 @@ $(window).ready(function() {
                                             setTimeout(function() { $(window).trigger("scroll"); }, 100);
                                         }
                                     });
-                                    
+
                                     highlightReply(post_response.id);
                                     window.location.hash = post_response.id;
                                     $(window).scrollTop($(document).height());
-                                    
+
                                     $(form).find('input[type="submit"]').val(submit_txt);
                                     $(form).find('input[type="submit"]').removeAttr('disabled');
                                     $(form).find('input[name="subject"],input[name="file_url"],\
@@ -132,10 +138,10 @@ $(window).ready(function() {
                 contentType: false,
                 processData: false
             }, 'json');
-            
+
             $(form).find('input[type="submit"]').val(_('Posting...'));
             $(form).find('input[type="submit"]').attr('disabled', true);
-            
+
             return false;
         });
     };