diff --git a/src/pyj/read_book/iframe.pyj b/src/pyj/read_book/iframe.pyj
index aec381c4c9..0c1d8d7823 100644
--- a/src/pyj/read_book/iframe.pyj
+++ b/src/pyj/read_book/iframe.pyj
@@ -155,6 +155,7 @@ class IframeBoss:
         self.last_cfi = None
         for name in self.blob_url_map:
             window.URL.revokeObjectURL(self.blob_url_map[name])
+        document.body.style.removeProperty('font-family')
         root_data, self.mathjax, self.blob_url_map = finalize_resources(self.book, data.name, data.resource_data)
         self.resource_urls = unserialize_html(root_data, self.content_loaded)