diff --git a/src/There4/Slim/Test/WebTestClient.php b/src/There4/Slim/Test/WebTestClient.php
index fa4784f..3668da8 100644
--- a/src/There4/Slim/Test/WebTestClient.php
+++ b/src/There4/Slim/Test/WebTestClient.php
@@ -88,6 +88,8 @@ private function request($method, $path, $data = array(), $optionalHeaders = arr
         $env = Slim\Environment::getInstance();
         $this->app->router = new NoCacheRouter($this->app->router);
         $this->app->request = new Slim\Http\Request($env);
+        // Custom headers
+        $this->app->request->headers = new Slim\Http\Headers($env);
         $this->app->response = new Slim\Http\Response();
 
         // Establish some useful references to the slim app properties