diff --git a/third_party/WebKit/LayoutTests/SlowTests b/third_party/WebKit/LayoutTests/SlowTests
index a52a8fd..89fd8c0 100644
--- a/third_party/WebKit/LayoutTests/SlowTests
+++ b/third_party/WebKit/LayoutTests/SlowTests
@@ -178,3 +178,4 @@
 crbug.com/372424 fast/dom/DOMImplementation/createDocument-with-used-doctype.html [ Slow ]
 
 crbug.com/372424 http/tests/serviceworker/chromium/registration-stress.html [ Slow ]
+crbug.com/448670 http/tests/serviceworker/chromium/register-different-script-many-times.html [ Slow ]