diff --git a/tests/end2end/data/prompt/clipboard.html b/tests/end2end/data/prompt/clipboard.html
index dd247eceb..fff148343 100644
--- a/tests/end2end/data/prompt/clipboard.html
+++ b/tests/end2end/data/prompt/clipboard.html
@@ -1,5 +1,8 @@
 <!DOCTYPE html>
-<!-- largely copied from https://googlechrome.github.io/samples/async-clipboard/ -->
+<!-- largely copied from https://googlechrome.github.io/samples/async-clipboard/
+SPDX-License-Identifier: Apache-2.0
+SPDX-FileCopyrightText: 2014 Google Inc
+-->
 <html>
     <head>
         <style type="text/css">
