add name that should be considered public to __all__
diff --git a/Lib/sgmllib.py b/Lib/sgmllib.py
index 7db0a97..08e365b 100644
--- a/Lib/sgmllib.py
+++ b/Lib/sgmllib.py
@@ -12,7 +12,7 @@
 import markupbase
 import re
 
-__all__ = ["SGMLParser"]
+__all__ = ["SGMLParser", "SGMLParseError"]
 
 # Regular expressions used for parsing