--- a/eric6/MicroPython/MicroPythonWidget.py	Tue May 12 17:32:16 2020 +0200
+++ b/eric6/MicroPython/MicroPythonWidget.py	Fri May 15 18:33:53 2020 +0200
@@ -327,10 +327,10 @@
         self.deviceTypeComboBox.setCurrentIndex(index)
         
         if unknownDevices:
-            ignoredUnknown = set([
+            ignoredUnknown = {
                 tuple(d)
                 for d in Preferences.getMicroPython("IgnoredUnknownDevices")
-            ])
+            }
             newUnknownDevices = set(unknownDevices) - ignoredUnknown
             if newUnknownDevices:
                 button = E5MessageBox.information(