diff --git a/package.json b/package.json
index 0e94757..42d270f 100644
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
         "postinstall": "base-volta-off-of-nwjs",
         "lint": "exit 0",
         "test": "vitest run",
-        "dev": "nw ./tests/fixtures/custom"
+        "dev": "nw ./tests/fixtures/nw/window"
     },
     "devDependencies": {
         "@types/chrome": "^0.0.270",
diff --git a/tests/fixtures/nw/window/index.html b/tests/fixtures/nw/window/index.html
new file mode 100644
index 0000000..4709f52
--- /dev/null
+++ b/tests/fixtures/nw/window/index.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <script>
+        let polyfill;
+        import('../../src/polyfill.js').then(module => {
+            polyfill = module.default;
+            polyfill();
+        });
+        document.addEventListener('DOMContentLoaded', () => {
+            const mainWindow = nw.Window.get();
+            mainWindow.showDevTools(() => {
+                document.getElementById('nw-window-isdevtoolsopen').innerText = mainWindow.isDevToolsOpen();
+            });
+        });
+    </script>
+    <title>nw.Window fixture</title>
+</head>
+
+<body>
+    <div>
+        <span>nw.Window.isDevToolsOpen: </span>
+        <span id="nw-window-isdevtoolsopen"></span>
+    </div>
+</body>
+
+</html>
diff --git a/tests/fixtures/nw/window/package.json b/tests/fixtures/nw/window/package.json
new file mode 100644
index 0000000..a236beb
--- /dev/null
+++ b/tests/fixtures/nw/window/package.json
@@ -0,0 +1,4 @@
+{
+    "name": "nw-app",
+    "main": "index.html"
+}
