diff --git a/gui/qt/util.py b/gui/qt/util.py
index 4998498d..754b4e04 100644
--- a/gui/qt/util.py
+++ b/gui/qt/util.py
@@ -85,28 +85,28 @@ class HelpButton(QPushButton):
 
 
 
-def close_button(dialog, label=_("Close") ):
+def close_button(dialog, label=None):
     hbox = QHBoxLayout()
     hbox.addStretch(1)
-    b = QPushButton(label)
+    b = QPushButton(label or _("Close"))
     hbox.addWidget(b)
     b.clicked.connect(dialog.close)
     b.setDefault(True)
     return hbox
 
-def ok_cancel_buttons2(dialog, ok_label=_("OK"), cancel_label=_('Cancel')):
+def ok_cancel_buttons2(dialog, ok_label=None, cancel_label=None):
     hbox = QHBoxLayout()
     hbox.addStretch(1)
-    b = QPushButton(cancel_label)
+    b = QPushButton(cancel_label or _('Cancel'))
     hbox.addWidget(b)
     b.clicked.connect(dialog.reject)
-    b = QPushButton(ok_label)
+    b = QPushButton(ok_label or _("OK"))
     hbox.addWidget(b)
     b.clicked.connect(dialog.accept)
     b.setDefault(True)
     return hbox, b
 
-def ok_cancel_buttons(dialog, ok_label=_("OK"), cancel_label=_('Cancel')):
+def ok_cancel_buttons(dialog, ok_label=None, cancel_label=None):
     hbox, b = ok_cancel_buttons2(dialog, ok_label, cancel_label)
     return hbox