diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index e59d78dd6f..7dc486bdb8 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -295,7 +295,7 @@ def apply_font_settings(page_or_view):
     if fs.get('mono_family'):
         s.setFontFamily(QWebEngineSettings.FontFamily.FixedFont, fs.get('mono_family'))
     else:
-        s.resetFontFamily(QWebEngineSettings.FontFamily.SansSerifFont)
+        s.resetFontFamily(QWebEngineSettings.FontFamily.FixedFont)
     sf = fs.get('standard_font') or 'serif'
     sf = getattr(QWebEngineSettings.FontFamily, {'serif': 'SerifFont', 'sans': 'SansSerifFont', 'mono': 'FixedFont'}[sf])
     s.setFontFamily(QWebEngineSettings.FontFamily.StandardFont, s.fontFamily(sf))