diff --git a/src/Potter/Message/MessageBodyInterface.php b/src/Potter/Message/MessageBodyInterface.php
new file mode 100644
index 0000000..6faeb9a
--- /dev/null
+++ b/src/Potter/Message/MessageBodyInterface.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Potter\Message;
+
+use \Psr\Http\Message\{
+    MessageInterface as PsrMessageInterface,
+    StreamInterface as PsrStreamInterface};
+
+interface MessageBodyInterface 
+{
+    public function getBody(): PsrStreamInterface;
+    public function withBody(StreamInterface $body): PsrMessageInterface;
+}
diff --git a/src/Potter/Message/MessageHeaderInterface.php b/src/Potter/Message/MessageHeaderInterface.php
new file mode 100644
index 0000000..64b6655
--- /dev/null
+++ b/src/Potter/Message/MessageHeaderInterface.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Potter\Message;
+
+use \Psr\Http\Message\MessageInterface as PsrMessageInterface;
+
+interface MessageHeaderInterface 
+{
+    public function getHeaders(): array;
+    public function hasHeader(string $name): bool;
+    public function getHeader(string $name): array;
+    public function getHeaderLine(string $name): string;
+    public function withHeader(string $name, $value): PsrMessageInterface;
+    public function withAddedHeader(string $name, $value): PsrMessageInterface;
+    public function withoutHeader(string $name): PsrMessageInterface;
+}
diff --git a/src/Potter/Message/MessageInterface.php b/src/Potter/Message/MessageInterface.php
new file mode 100644
index 0000000..8667d14
--- /dev/null
+++ b/src/Potter/Message/MessageInterface.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Potter\Message;
+
+use \Psr\Http\Message\MessageInterface as PsrMessageInterface;
+
+interface MessageInterface extends PsrMessageInterface,
+    MessageProtocolInterface, MessageHeaderInterface, MessageBodyInterface
+{ }
diff --git a/src/Potter/Message/MessageProtocolInterface.php b/src/Potter/Message/MessageProtocolInterface.php
new file mode 100644
index 0000000..1e0d55e
--- /dev/null
+++ b/src/Potter/Message/MessageProtocolInterface.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Potter\Message;
+
+use \Psr\Http\Message\MessageInterface as PsrMessageInterface;
+
+interface MessageProtocolInterface 
+{
+    public function getProtocolVersion(): string;
+    public function withProtocolVersion(string $version): PsrMessageInterface;
+}