1 files changed, 1 insertions, 1 deletions
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_streamfilter_processswitch.html b/toolkit/components/extensions/test/mochitest/test_ext_streamfilter_processswitch.html
index 049178cad0..7240e01c02 100644
--- a/toolkit/components/extensions/test/mochitest/test_ext_streamfilter_processswitch.html
+++ b/toolkit/components/extensions/test/mochitest/test_ext_streamfilter_processswitch.html
@@ -36,7 +36,7 @@ add_task(async () => {
           filter.ondata = event => {
             filter.write(event.data);
           };
-          filter.onstop = event => {
+          filter.onstop = () => {
             filter.write(new TextEncoder().encode(" End"));
             filter.close();
           };