diff -up system-config-printer-1.4.1/newprinter.py.nested-class system-config-printer-1.4.1/newprinter.py
--- system-config-printer-1.4.1/newprinter.py.nested-class	2017-11-03 14:57:39.481589227 +0100
+++ system-config-printer-1.4.1/newprinter.py	2017-11-03 15:00:20.885299434 +0100
@@ -827,7 +827,8 @@ class NewPrinterGUI(GtkGUI):
             self.printers = {}
 
         for printer in self.printers.keys():
-            model.append((printer,))
+            if not self.printers[printer].type & cups.CUPS_PRINTER_CLASS:
+                model.append((printer,))
 
     def on_btnNCAddMember_clicked(self, button):
         moveClassMembers(self.tvNCNotMembers, self.tvNCMembers)
diff -up system-config-printer-1.4.1/printerproperties.py.nested-class system-config-printer-1.4.1/printerproperties.py
--- system-config-printer-1.4.1/printerproperties.py.nested-class	2017-11-03 14:57:50.936497690 +0100
+++ system-config-printer-1.4.1/printerproperties.py	2017-11-03 14:59:18.429798522 +0100
@@ -1820,7 +1820,7 @@ class PrinterPropertiesDialog(GtkGUI):
             if name != self.printer.name:
                 if name in self.printer.class_members:
                     model_members.append((name, ))
-                else:
+                elif not self.printer.type & cups.CUPS_PRINTER_CLASS:
                     model_not_members.append((name, ))
 
     def on_btnClassAddMember_clicked(self, button):