diff --git a/web/index.php b/web/index.php
index 6167dc4dc..4b9ab3409 100644
--- a/web/index.php
+++ b/web/index.php
@@ -57,6 +57,7 @@ else
 {
     $protocol = 'http';
 }
+define( "ZM_BASE_PROTOCOL", $protocol );
 define( "ZM_BASE_URL", $protocol.'://'.$_SERVER['HTTP_HOST'] );
 
 if ( isset($_GET['skin']) )