diff --git a/lib/Loop/Driver.php b/lib/Loop/Driver.php
index e78a8fd..017eb69 100644
--- a/lib/Loop/Driver.php
+++ b/lib/Loop/Driver.php
@@ -87,21 +87,37 @@ abstract class Driver
      */
     public function createControl(): DriverControl
     {
-        return new DriverControl(
-            function () use (&$running) {
-                $running = true;
-                while ($running) {
-                    if ($this->isEmpty()) {
-                        return;
-                    }
-
-                    $this->tick();
+        return new class(function () use (&$running) {
+            $running = true;
+            while ($running) {
+                if ($this->isEmpty()) {
+                    return;
                 }
-            },
-            static function () use (&$running) {
-                $running = false;
+
+                $this->tick();
             }
-        );
+        }, static function () use (&$running) {
+            $running = false;
+        }) implements DriverControl {
+            private $run;
+            private $stop;
+
+            public function __construct(callable $run, callable $stop)
+            {
+                $this->run = $run;
+                $this->stop = $stop;
+            }
+
+            public function run()
+            {
+                ($this->run)();
+            }
+
+            public function stop()
+            {
+                ($this->stop)();
+            }
+        };
     }
 
     /**
diff --git a/lib/Loop/DriverControl.php b/lib/Loop/DriverControl.php
index 73c551f..bf611cb 100644
--- a/lib/Loop/DriverControl.php
+++ b/lib/Loop/DriverControl.php
@@ -2,24 +2,23 @@
 
 namespace Amp\Loop;
 
-final class DriverControl
+interface DriverControl
 {
-    private $run;
-    private $stop;
+    /**
+     * Run the driver event loop.
+     *
+     * @return void
+     *
+     * @see Driver::run()
+     */
+    public function run();
 
-    public function __construct(callable $run, callable $stop)
-    {
-        $this->run = $run;
-        $this->stop = $stop;
-    }
-
-    public function run()
-    {
-        ($this->run)();
-    }
-
-    public function stop()
-    {
-        ($this->stop)();
-    }
+    /**
+     * Stop the driver event loop.
+     *
+     * @return void
+     *
+     * @see Driver::stop()
+     */
+    public function stop();
 }