diff --git a/package.json b/package.json
index 02d16f0f47..f886a96aff 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "lazypipe": "^0.2.3",
     "polyclean": "^1.2.0",
     "run-sequence": "^1.1.0",
-    "web-component-tester": "^3.3.21"
+    "web-component-tester": "^4"
   },
   "scripts": {
     "build": "gulp",
diff --git a/test/unit/globals.html b/test/unit/globals.html
index cb15ad9841..3978314b2b 100644
--- a/test/unit/globals.html
+++ b/test/unit/globals.html
@@ -40,6 +40,11 @@
     // Polymer
     Polymer: true,
     currentImport: true
+
+    // weird safari + selenium globals
+    alert: true,
+    confirm: true,
+    prompt: true
   };
 
   test('check global leakage', function() {