diff --git a/invesalius/gui/dialogs.py b/invesalius/gui/dialogs.py
index 3d3cba4..7e10535 100644
--- a/invesalius/gui/dialogs.py
+++ b/invesalius/gui/dialogs.py
@@ -1404,7 +1404,11 @@ class MaskBooleanDialog(wx.Dialog):
             self.mask2.Append(n, m)
 
         self.mask1.SetSelection(0)
-        self.mask2.SetSelection(0)
+
+        if len(mask_choices) > 1:
+            self.mask2.SetSelection(1)
+        else:
+            self.mask2.SetSelection(0)
 
         op_choices = ((u"Union", const.BOOLEAN_UNION),
                       (u"Difference", const.BOOLEAN_DIFF), 
diff --git a/invesalius/gui/frame.py b/invesalius/gui/frame.py
index f6f645c..d860192 100644
--- a/invesalius/gui/frame.py
+++ b/invesalius/gui/frame.py
@@ -609,7 +609,7 @@ class MenuBar(wx.MenuBar):
         #app(const.ID_EDIT_LIST, "Show Undo List...")
         #################################################################
 
-        file_edit.Append(const.ID_BOOLEAN_MASK, _(u"\tBoolean operations"))
+        file_edit.Append(const.ID_BOOLEAN_MASK, _(u"Boolean operations"))
 
 
         # VIEW
--
libgit2 0.21.2