diff --git a/FlatCAMWorkerStack.py b/FlatCAMWorkerStack.py
index 142cd9b1..3ce56011 100644
--- a/FlatCAMWorkerStack.py
+++ b/FlatCAMWorkerStack.py
@@ -25,7 +25,7 @@ class WorkerStack(QtCore.QObject):
             thread.started.connect(worker.run)
             worker.task_completed.connect(self.on_task_completed)
 
-            thread.start(QtCore.QThread.HighPriority)
+            thread.start(QtCore.QThread.NormalPriority)
 
             self.workers.append(worker)
             self.threads.append(thread)
diff --git a/README.md b/README.md
index 7a05a45e..fb8c4767 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ CAD program, and create G-Code for Isolation routing.
 - added progress for the generation of Isolation geometry
 - added progress and possibility of graceful exit in Panel Tool
 - added graceful exit possibility when creating Isolation
+- chagend the workers thread priority back to Normal
 
 9.09.2019