--- a/eric6/Plugins/VcsPlugins/vcsMercurial/HgCommandDialog.py	Mon Mar 01 17:48:43 2021 +0100
+++ b/eric6/Plugins/VcsPlugins/vcsMercurial/HgCommandDialog.py	Tue Mar 02 17:17:09 2021 +0100
@@ -34,7 +34,8 @@
         super(HgCommandDialog, self).__init__(parent)
         self.setupUi(self)
         
-        self.okButton = self.buttonBox.button(QDialogButtonBox.Ok)
+        self.okButton = self.buttonBox.button(
+            QDialogButtonBox.StandardButton.Ok)
         self.okButton.setEnabled(False)
         
         self.commandCombo.clear()