diff --git a/src/calibre/gui2/dialogs/template_dialog.py b/src/calibre/gui2/dialogs/template_dialog.py
index f0414ebb0b..ba941f7d84 100644
--- a/src/calibre/gui2/dialogs/template_dialog.py
+++ b/src/calibre/gui2/dialogs/template_dialog.py
@@ -114,7 +114,7 @@ class TemplateHighlighter(QSyntaxHighlighter):
             config["%sfontbold" % name] = bold
             config["%sfontitalic" % name] = italic
         base_format = QTextCharFormat()
-        base_format.setFontFamily(config["fontfamily"])
+        base_format.setFontFamilies([config["fontfamily"]])
         config["fontsize"] = size
         base_format.setFontPointSize(config["fontsize"])
 
diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index e9255c7f16..d533fa5864 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -880,7 +880,7 @@ class PythonHighlighter(QSyntaxHighlighter):  # {{{
     @classmethod
     def initializeFormats(cls):
         baseFormat = QTextCharFormat()
-        baseFormat.setFontFamily('monospace')
+        baseFormat.setFontFamilies(['monospace'])
         p = QApplication.instance().palette()
         for name, color, bold, italic in (
                 ("normal", None, False, False),