--- a/eric6/UI/DiffDialog.py	Mon Oct 12 17:23:15 2020 +0200
+++ b/eric6/UI/DiffDialog.py	Mon Oct 12 17:39:45 2020 +0200
@@ -7,7 +7,6 @@
 Module implementing a dialog to compare two files.
 """
 
-
 import os
 import time
 
@@ -64,8 +63,7 @@
         self.updateInterval = 20    # update every 20 lines
         
         font = Preferences.getEditorOtherFonts("MonospacedFont")
-        self.contents.setFontFamily(font.family())
-        self.contents.setFontPointSize(font.pointSize())
+        self.contents.document().setDefaultFont(font)
         
         self.highlighter = DiffHighlighter(self.contents.document())