diff --git a/mollom.module b/mollom.module
index 95f9468..21510d6 100644
--- a/mollom.module
+++ b/mollom.module
@@ -2323,7 +2323,7 @@ function mollom_get_captcha(&$form_state) {
         'query' => array('url' => $url),
         'external' => TRUE,
       ));
-      $output = '<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="110" height="50">';
+      $output = '<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="//download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="110" height="50">';
       $output .= '<param name="allowFullScreen" value="false" />';
       $output .= '<param name="movie" value="' . $source . '" />';
       $output .= '<param name="loop" value="false" />';