diff --git a/util/html.py b/util/html.py
index b0e3d43..1d0a7fe 100644
--- a/util/html.py
+++ b/util/html.py
@@ -83,10 +83,10 @@ class HTMLToTokensParser(HTMLParser):
     def handle_endtag(self, tag: str) -> None:
         if self.invisible:
             if tag == self.invisible:
-                if self.invisible_depth == 0:
+                if self.invisible_depth <= 0:
                     self.invisible = None
                 else:
-                    self.invisible_depth = -1
+                    self.invisible_depth -= 1
             return
 
         match tag: