diff --git a/.travis.yml b/.travis.yml
index a919868..b644a47 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
 
 env:
   - DEPS=lowest
diff --git a/composer.json b/composer.json
index c716d8f..4ab02f2 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         "http-interop/http-middleware": "^0.4.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.6 || ^6.1.3",
+        "phpunit/phpunit": "^5.7.27 || ^6.1.3",
         "ramsey/uuid": "^3.0",
         "zendframework/zend-diactoros": "^1.1.3"
     },
diff --git a/src/RequestIdMiddleware.php b/src/RequestIdMiddleware.php
index 3a503d2..c45f0d7 100644
--- a/src/RequestIdMiddleware.php
+++ b/src/RequestIdMiddleware.php
@@ -7,6 +7,7 @@
 use PhpMiddleware\DoublePassCompatibilityTrait;
 use PhpMiddleware\RequestId\Exception\NotGenerated;
 use PhpMiddleware\RequestId\RequestIdProviderFactoryInterface;
+use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 
@@ -60,7 +61,7 @@ public function process(ServerRequestInterface $request, DelegateInterface $dele
     }
 
     /**
-     * @return ResponseInterface
+     * @return RequestInterface
      */
     private function attachRequestIdToAttribute(ServerRequestInterface $request)
     {