diff --git a/pym/consolegui/application/mainframe.py b/pym/consolegui/application/mainframe.py
index 4de0b71..5e2740e 100644
--- a/pym/consolegui/application/mainframe.py
+++ b/pym/consolegui/application/mainframe.py
@@ -2425,15 +2425,24 @@ class MainFrame(qt.QWidget):
 
                     elif type(self.view_dict[field.name]) == qt.QCheckBox:
                         if self.view_dict[field.name].isTristate():
-                            if self.view_dict[field.name].checkState() \
-                                    == qt.Qt.PartiallyChecked:
-                                param_object[paramname] = None
-                            elif self.view_dict[field.name].checkState() \
-                                    == qt.Qt.Checked:
-                                param_object[paramname] = True
+                            if field.type == "bool3":
+                                if self.view_dict[field.name].checkState() \
+                                        == qt.Qt.PartiallyChecked:
+                                    param_object[paramname] = "auto"
+                                elif self.view_dict[field.name].checkState() \
+                                        == qt.Qt.Checked:
+                                    param_object[paramname] = "on"
+                                else:
+                                    param_object[paramname] = "off"
                             else:
-                                param_object[paramname] = False
-
+                                if self.view_dict[field.name].checkState() \
+                                        == qt.Qt.PartiallyChecked:
+                                    param_object[paramname] = None
+                                elif self.view_dict[field.name].checkState() \
+                                        == qt.Qt.Checked:
+                                    param_object[paramname] = True
+                                else:
+                                    param_object[paramname] = False
                         else:
                             param_object[paramname] = \
                                 self.view_dict[field.name].isChecked()