diff --git a/src/Illuminate/Http/RedirectResponse.php b/src/Illuminate/Http/RedirectResponse.php
index 0c71743dd62f..37093e94ea50 100755
--- a/src/Illuminate/Http/RedirectResponse.php
+++ b/src/Illuminate/Http/RedirectResponse.php
@@ -131,9 +131,14 @@ public function exceptInput()
     public function withErrors($provider, $key = 'default')
     {
         $value = $this->parseErrors($provider);
+        $errors = $this->session->get('errors', new ViewErrorBag);
+
+        if (! ($errors instanceof ViewErrorBag)) {
+            $errors = new ViewErrorBag;
+        }
 
         $this->session->flash(
-            'errors', $this->session->get('errors', new ViewErrorBag)->put($key, $value)
+            'errors', $errors->put($key, $value)
         );
 
         return $this;