diff --git a/course/category.php b/course/category.php
index d0a3664..bdc6b9c 100644
--- a/course/category.php
+++ b/course/category.php
@@ -91,7 +91,7 @@
 	while ($cattree->parent) {
 		$cattree = get_record("course_categories", "id", $cattree->parent);
 		$cattype = $cattree->visible ? "category" : "hiddencategory";
-		array_unshift($navlinks, array('name' => format_string($cattree->name), 'link' => "category.php?id=$cattree->id", 'type' => $cattype));
+		array_unshift($navlinks, array('name' => format_string($cattree->name), 'link' => "$CFG->wwwroot/course/category.php?id=$cattree->id", 'type' => $cattype));
 	}
     $navigation = build_navigation($navlinks);
 
diff --git a/lib/weblib.php b/lib/weblib.php
index ae69295..3bf3ed2 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -3809,11 +3809,11 @@ function build_navigation($extranavlinks, $cm = null) {
         $catlinks = array();
         if ($cattree = get_record("course_categories", "id", $COURSE->category)) {
             $cattype = $cattree->visible ? "category" : "hiddencategory";
-            $catlinks[] = array('name' => $cattree->name, 'link' => "category.php?id=$cattree->id", 'type' => $cattype);
+            $catlinks[] = array('name' => $cattree->name, 'link' => "$CFG->wwwroot/course/category.php?id=$cattree->id", 'type' => $cattype);
             while ($cattree->parent) {
                 $cattree = get_record("course_categories", "id", $cattree->parent);
                 $cattype = $cattree->visible ? "category" : "hiddencategory";
-                array_unshift($catlinks, array('name' => $cattree->name, 'link' => "category.php?id=$cattree->id", 'type' => $cattype));
+                array_unshift($catlinks, array('name' => $cattree->name, 'link' => "$CFG->wwwroot/course/category.php?id=$cattree->id", 'type' => $cattype));
             }
         }
         $navlinks = array_merge($navlinks, $catlinks);