diff --git a/testing/taskcluster/tasks/tests/fx_linux64_mochitest_plain.yml b/testing/taskcluster/tasks/tests/fx_linux64_mochitest_plain.yml
index d117ecbe247f..1ee66af77d64 100644
--- a/testing/taskcluster/tasks/tests/fx_linux64_mochitest_plain.yml
+++ b/testing/taskcluster/tasks/tests/fx_linux64_mochitest_plain.yml
@@ -15,7 +15,7 @@ task:
         loopbackAudio: true
   extra:
     chunks:
-      total: 5
+      total: 8
     suite:
       name: mochitest
       flavor: plain-chunked