diff --git a/Lib/html/parser.py b/Lib/html/parser.py
index ef869bc72db..de81879a631 100644
--- a/Lib/html/parser.py
+++ b/Lib/html/parser.py
@@ -418,7 +418,7 @@ def parse_endtag(self, i):
                 self.handle_data(rawdata[i:gtpos])
                 return gtpos
 
-        self.handle_endtag(elem.lower())
+        self.handle_endtag(elem)
         self.clear_cdata_mode()
         return gtpos