diff --git a/render/Router.php b/render/Router.php
index <HASH>..<HASH> 100644
--- a/render/Router.php
+++ b/render/Router.php
@@ -106,7 +106,9 @@ class Router
                     }
                     $newurl = $url;
                     foreach ($this->translations['slugs'] as $match => $value) {
-                        if (preg_match("@/$match(/|^)@", $newurl, $matches)) {
+                        if (preg_match("@/$match(/|^)@", $newurl, $matches)
+                            && isset($value[$lang->code])
+                        ) {
                             $newurl = preg_replace(
                                 "@/$match(/|^)@",
                                 "/{$value[$lang->code]}\\1",
Squashed commit of the following:

commit c<I>a2bbd<I>becb<I>e<I>f<I>d<I>a5d<I>