diff --git a/src/calibre/ebooks/conversion/plugins/html_input.py b/src/calibre/ebooks/conversion/plugins/html_input.py
index 5717e79b24..4439456a08 100644
--- a/src/calibre/ebooks/conversion/plugins/html_input.py
+++ b/src/calibre/ebooks/conversion/plugins/html_input.py
@@ -22,7 +22,7 @@ from calibre.utils.imghdr import what
 def sanitize_file_name(x):
     ans = re.sub(r'\s+', ' ', re.sub(r'[?&=;#]', '_', ascii_filename(x))).strip().rstrip('.')
     ans, ext = ans.rpartition('.')[::2]
-    return ans.strip() + '.' + ext.strip()
+    return (ans.strip() + '.' + ext.strip()).rstrip('.')
 
 
 class HTMLInput(InputFormatPlugin):