diff --git a/embroider_params.py b/embroider_params.py
index 8300cbc24..ffd9d53ae 100644
--- a/embroider_params.py
+++ b/embroider_params.py
@@ -388,7 +388,7 @@ class SettingsFrame(wx.Frame):
     def update_patches(self):
         patches = self.generate_patches()
 
-        if patches:
+        if patches and not self.simulate_refresh_needed.is_set():
             wx.CallAfter(self.refresh_simulator, patches)
 
     def refresh_simulator(self, patches):