diff --git a/src/DebugBar/DebugBar.php b/src/DebugBar/DebugBar.php
index 42ba2e7..a8ecb79 100644
--- a/src/DebugBar/DebugBar.php
+++ b/src/DebugBar/DebugBar.php
@@ -490,7 +490,7 @@ class DebugBar implements ArrayAccess
      */
     public static function hasDataHasher() : bool
     {
-        return static::$dataHasher !== null;
+        return isset(static::$dataHasher);
     }
 
     /**
@@ -500,7 +500,7 @@ class DebugBar implements ArrayAccess
      */
     public static function getDataHasher() : DataHasher
     {
-        if (static::$dataHasher === null) {
+        if (!isset(static::$dataHasher)) {
             throw new DebugBarException('DataHasher is not set');
         }
         return static::$dataHasher;
diff --git a/src/DebugBar/OpenHandler.php b/src/DebugBar/OpenHandler.php
index 5b48d5a..4347dab 100644
--- a/src/DebugBar/OpenHandler.php
+++ b/src/DebugBar/OpenHandler.php
@@ -129,7 +129,7 @@ class OpenHandler
     protected function execute($request)
     {
         if (!isset($request['collector']) || !isset($request['action']) || !isset($request['signature'])) {
-            throw new DebugBarException("Missing 'collector' and/or 'action' parameter in 'execute' operation");
+            throw new DebugBarException("Missing 'collector', 'action' and/or 'signature' parameter in 'execute' operation");
         }
 
         if (!DebugBar::hasDataHasher()) {
diff --git a/tests/DebugBar/Tests/DataCollector/MockActionCollector.php b/tests/DebugBar/Tests/DataCollector/MockActionCollector.php
new file mode 100644
index 0000000..0866941
--- /dev/null
+++ b/tests/DebugBar/Tests/DataCollector/MockActionCollector.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace DebugBar\Tests\DataCollector;
+
+use DebugBar\DataCollector\Actionable;
+
+class MockActionCollector extends MockCollector implements Actionable
+{
+
+    function executionAction($action, array $payload = null)
+    {
+        return ['result' => 'done'];
+    }
+}
diff --git a/tests/DebugBar/Tests/OpenHandlerTest.php b/tests/DebugBar/Tests/OpenHandlerTest.php
index cb0ea3b..a105012 100644
--- a/tests/DebugBar/Tests/OpenHandlerTest.php
+++ b/tests/DebugBar/Tests/OpenHandlerTest.php
@@ -2,9 +2,12 @@
 
 namespace DebugBar\Tests;
 
+use DebugBar\DataHasher;
 use DebugBar\DebugBar;
 use DebugBar\DebugBarException;
 use DebugBar\OpenHandler;
+use DebugBar\Tests\DataCollector\MockActionCollector;
+use DebugBar\Tests\DataCollector\MockCollector;
 use DebugBar\Tests\Storage\MockStorage;
 
 class OpenHandlerTest extends DebugBarTestCase
@@ -47,4 +50,40 @@ class OpenHandlerTest extends DebugBarTestCase
         $result = $this->openHandler->handle(array('op' => 'clear'), false, false);
         $this->assertJsonPropertyEquals($result, 'success', true);
     }
+
+    public function testExecute()
+    {
+        $this->debugbar->addCollector(new MockActionCollector([], 'mock-action'));
+        $dataHasher = new DataHasher('secret');
+        DebugBar::setDataHasher($dataHasher);
+
+        $data = [
+            'op' => 'execute',
+            'collector' => 'mock-action',
+            'action' => 'run',
+        ];
+
+        $data['signature'] = $dataHasher->sign($data);
+
+        $result = $this->openHandler->handle($data, false, false);
+        $this->assertJsonPropertyEquals($result, 'result', 'done');
+    }
+
+    public function testExecuteWrongSignature()
+    {
+        $this->debugbar->addCollector(new MockActionCollector([], 'mock-action'));
+        $dataHasher = new DataHasher('secret');
+        DebugBar::setDataHasher($dataHasher);
+
+        $data = [
+            'op' => 'execute',
+            'collector' => 'mock-action',
+            'action' => 'run',
+            'signature' => 'invalid',
+        ];
+
+        $this->expectExceptionMessage("Signature does not match in 'execute' operation");
+        
+        $this->openHandler->handle($data, false, false);
+    }
 }