diff --git a/src/WatcherInterface.php b/src/WatcherInterface.php
new file mode 100644
index 0000000..a41e9d0
--- /dev/null
+++ b/src/WatcherInterface.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Interop\Async\EventLoop;
+
+interface WatcherInterface
+{
+    /**
+     * @return void
+     */
+    public function enable();
+
+    /**
+     * @return void
+     */
+    public function disable();
+
+    /**
+     * @return void
+     */
+    public function cancel();
+}