diff --git a/etc/taskcluster/decision_task.py b/etc/taskcluster/decision_task.py
index 4a3537e9abf..f5f165575d8 100644
--- a/etc/taskcluster/decision_task.py
+++ b/etc/taskcluster/decision_task.py
@@ -569,7 +569,7 @@ def wpt_chunks(platform, make_chunk_task, build_task, total_chunks, processes,
                     tests/wpt/mozilla/tests/css/img_simple.html \
                     tests/wpt/mozilla/tests/mozilla/secure.https.html \
                     | cat
-                time ./mach test-wpt --release --processes 1 --product=servodriver \
+                time ./mach test-wpt --release --processes $PROCESSES --product=servodriver \
                     --headless --log-raw test-bluetooth.log \
                     --log-errorsummary bluetooth-errorsummary.log \
                     bluetooth \