diff --git a/auth.php b/auth.php
index 5661d88..5e1bca5 100644
--- a/auth.php
+++ b/auth.php
@@ -94,7 +94,8 @@ class auth
     if ($url === "")
       $res .= "#";
     else
-      $res .= $baseURL."authentication/$url";
+      $res .= $baseURL."authentication/".
+              str_replace ("%2F", "/", urlencode ($url));
     $res .= "'>\n";
     if ($alreadyAuth === false)
     {
@@ -123,7 +124,8 @@ class auth
       $res .= "    <p><a href='". $baseURL."authentication/logout'>".
               dgettext ("domframework", "Logout")."</a>\n";
       if ($url !== "")
-        $res .= "<a href='$baseURL$url'>".
+        $res .= "<a href='$baseURL".
+                str_replace ("%2F", "/", urlencode ($url))."'>".
                 dgettext ("domframework", "Go back to the calling page").
                 "</a>\n";
       $res .="</p>\n";