diff --git a/etc/taskcluster/decision_task.py b/etc/taskcluster/decision_task.py
index 0d041e089d1a..f0e135de2d3c 100644
--- a/etc/taskcluster/decision_task.py
+++ b/etc/taskcluster/decision_task.py
@@ -543,7 +543,7 @@ def macos_run_task(name):
         build_task,
         repo_dir="repo",
         total_chunks=20,
-        processes=8,
+        processes=4,
     )