diff --git a/bookmarks.php b/bookmarks.php
index a5f384e..91d0999 100644
--- a/bookmarks.php
+++ b/bookmarks.php
@@ -207,7 +207,10 @@ if ($templatename == 'editbookmark.tpl') {
 				
 		}
 		$title = T_('Add a Bookmark');
-		$tplVars['referrer'] = $_SERVER['HTTP_REFERER'];
+		$tplVars['referrer'] = '';;
+		if (isset($_SERVER['HTTP_REFERER'])) {
+			$tplVars['referrer'] = $_SERVER['HTTP_REFERER'];
+		}
 		$tplVars['pagetitle'] = $title;
 		$tplVars['subtitle'] = $title;
 		$tplVars['btnsubmit'] = T_('Add Bookmark');
diff --git a/edit.php b/edit.php
index 76a977c..005493d 100644
--- a/edit.php
+++ b/edit.php
@@ -112,7 +112,10 @@ if (!($row = $bookmarkservice->getBookmark(intval($bookmark), true))) {
     $tplVars['formaction']  = createURL('edit', $bookmark);
     $tplVars['btnsubmit'] = T_('Save Changes');
     $tplVars['showdelete'] = true;
-    $tplVars['referrer'] = $_SERVER['HTTP_REFERER'];
+    $tplVars['referrer'] = '';
+    if (isset($_SERVER['HTTP_REFERER'])) {
+        $tplVars['referrer'] = $_SERVER['HTTP_REFERER'];
+    }
     $templateservice->loadTemplate('editbookmark.tpl', $tplVars);
 }
 ?>