diff --git a/src/Browser/BrowserContext.php b/src/Browser/BrowserContext.php
index 066186d..9f20252 100644
--- a/src/Browser/BrowserContext.php
+++ b/src/Browser/BrowserContext.php
@@ -85,6 +85,9 @@ public function dispatchEvent(string $eventName, array $params): void
         if ('binding' === $eventName) {
             $bindingName = $params['name'];
             if (is_string($bindingName) && isset($this->bindings[$bindingName]) && is_callable($this->bindings[$bindingName])) {
+                if (!is_string($params['pageId'])) {
+                    throw new ProtocolErrorException('Invalid pageId in binding event', 0);
+                }
                 $source = [
                     'context' => $this,
                     'page' => $this->pages[$params['pageId']] ?? null,
diff --git a/src/Transport/JsonRpc/JsonRpcTransport.php b/src/Transport/JsonRpc/JsonRpcTransport.php
index af3a8f8..829566f 100644
--- a/src/Transport/JsonRpc/JsonRpcTransport.php
+++ b/src/Transport/JsonRpc/JsonRpcTransport.php
@@ -272,6 +272,12 @@ private function handleEvent(array $event): void
         }
 
         $objectId = $event['objectId'];
+        if (!is_string($objectId)) {
+            $this->logger->warning('Invalid objectId in event', ['event' => $event]);
+
+            return;
+        }
+
         if (isset($this->eventDispatchers[$objectId])) {
             $this->logger->debug('Dispatching event to registered handler', [
                 'objectId' => $objectId,
diff --git a/tests/Integration/Browser/BrowserContextTest.php b/tests/Integration/Browser/BrowserContextTest.php
index 907880f..86e47c6 100644
--- a/tests/Integration/Browser/BrowserContextTest.php
+++ b/tests/Integration/Browser/BrowserContextTest.php
@@ -133,7 +133,17 @@ public function itSetsGeolocation(): void
 
         $page->click('button');
 
-        usleep(500000);
+        // Poll for either coordinates or error text since Page::waitForFunction is not available
+        $deadline = microtime(true) + 5.0; // 5 seconds
+        do {
+            $content = $page->content() ?? '';
+            $hasCoordinates = str_contains($content, '59.95,30.31667');
+            $hasError = str_contains($content, 'Error');
+            if ($hasCoordinates || $hasError) {
+                break;
+            }
+            usleep(100 * 1000); // 100ms
+        } while (microtime(true) < $deadline);
 
         $content = $page->content();
         $hasCoordinates = str_contains($content, '59.95,30.31667');
diff --git a/tests/Integration/Locator/LocatorTest.php b/tests/Integration/Locator/LocatorTest.php
index 2dd9cb5..543382f 100644
--- a/tests/Integration/Locator/LocatorTest.php
+++ b/tests/Integration/Locator/LocatorTest.php
@@ -168,6 +168,16 @@ public function itTakesAScreenshotOfAnElement(): void
         $this->assertStringStartsWith(base64_decode('iVBORw0KGgo='), base64_decode($binary));
     }
 
+    #[Test]
+    public function itEvaluatesElementTagNameAndCss(): void
+    {
+        $tagName = $this->page->locator('h1')->evaluate('element => element.tagName');
+        $this->assertEquals('H1', $tagName);
+
+        $width = $this->page->locator('#div-1')->evaluate('element => window.getComputedStyle(element).width');
+        $this->assertEquals('50px', $width);
+    }
+
     private static function findFreePort(): int
     {
         return 0;