--- a/eric6/Plugins/VcsPlugins/vcsSubversion/SvnMergeDialog.py	Mon Mar 01 17:48:43 2021 +0100
+++ b/eric6/Plugins/VcsPlugins/vcsSubversion/SvnMergeDialog.py	Tue Mar 02 17:17:09 2021 +0100
@@ -46,7 +46,8 @@
         self.targetCombo.clear()
         self.targetCombo.addItems(targetlist)
         
-        self.okButton = self.buttonBox.button(QDialogButtonBox.Ok)
+        self.okButton = self.buttonBox.button(
+            QDialogButtonBox.StandardButton.Ok)
         self.okButton.setEnabled(False)
         
         msh = self.minimumSizeHint()