diff --git a/docs/index.md b/docs/index.md
index b06ec9d..311a05b 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -378,7 +378,6 @@ namespace Acme\Action;
 use Acme\Domain\Authentication;
 use Acme\Input\LoginInput;
 use Equip\Contract\ActionInterface;
-use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 
@@ -402,7 +401,7 @@ class LoginAction implements ActionInterface
         $this->responder = $responder;
     }
 
-    public function __invoke(RequestInterface $request, ResponseInterface $response)
+    public function __invoke(ServerRequestInterface $request, ResponseInterface $response)
     {
         $input = $this->input($request);
         $errors = $this->auth->validate($input);
diff --git a/src/Contract/ActionInterface.php b/src/Contract/ActionInterface.php
index f3b6b70..ffbc591 100644
--- a/src/Contract/ActionInterface.php
+++ b/src/Contract/ActionInterface.php
@@ -2,7 +2,7 @@
 
 namespace Equip\Contract;
 
-use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Message\ResponseInterface;
 
 interface ActionInterface
@@ -13,13 +13,13 @@ interface ActionInterface
      * Parses request input and invokes domain logic. Formats domain output for
      * the response.
      *
-     * @param RequestInterface $request
+     * @param ServerRequestInterface $request
      * @param ResponseInterface $response
      *
      * @return ResponseInterface
      */
     public function __invoke(
-        RequestInterface $request,
+        ServerRequestInterface $request,
         ResponseInterface $response
     );
 }