diff --git a/package.json b/package.json
index 793638d..7221987 100644
--- a/package.json
+++ b/package.json
@@ -73,7 +73,7 @@
     "url-loader": "0.5.8",
     "validate-commit-msg": "2.11.2",
     "wct-sauce": "2.0.0-pre.1",
-    "web-component-tester": "5.0.1",
+    "web-component-tester": "6.3.0",
     "webpack": "2.2.1",
     "webpack-config-utils": "2.3.0",
     "webpack-dev-server": "2.4.1",