diff --git a/lib/base.php b/lib/base.php
index 94fb7979620bbf2ffee6201c70c2c8ed083462ed..ef203b33c2b1b45846d7edb54f789e16971a2e7c 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -557,7 +557,9 @@ class OC
             OC_App::loadApps();
             OC_User::setupBackends();
             if (isset($_GET["logout"]) and ($_GET["logout"])) {
-                OC_Preferences::deleteKey(OC_User::getUser(), 'login_token', $_COOKIE['oc_token']);
+		if (isset($_COOKIE['oc_token'])) {
+			OC_Preferences::deleteKey(OC_User::getUser(), 'login_token', $_COOKIE['oc_token']);
+		}
                 OC_User::logout();
                 header("Location: " . OC::$WEBROOT . '/');
             } else {