diff --git a/src/Router.php b/src/Router.php
index d40ee99..d005c19 100644
--- a/src/Router.php
+++ b/src/Router.php
@@ -116,6 +116,8 @@ public function singleRequest($method, $uri, array $data = [], array $headers =
         // after we've completed our internal request.
         $currentRequest = $this->request->instance()->duplicate();
 
+        $headers = $this->overrideHeaders($currentRequest->headers->all(), $headers);
+
         if ($this->disableMiddleware) {
             $this->app->instance('middleware.disable', true);
         }
@@ -141,6 +143,11 @@ public function singleRequest($method, $uri, array $data = [], array $headers =
         return $response;
     }
 
+    private function overrideHeaders(array $default, array $headers)
+    {
+        return array_merge($default, $headers);
+    }
+
     public function enableMiddleware()
     {
         $this->disableMiddleware = false;