diff --git a/src/antlr4/tree/Tree.py b/src/antlr4/tree/Tree.py
index a5bd3e3886..b26aeb1dcc 100644
--- a/src/antlr4/tree/Tree.py
+++ b/src/antlr4/tree/Tree.py
@@ -86,6 +86,8 @@ def aggregateResult(self, aggregate, nextResult):
     def shouldVisitNextChild(self, node, currentResult):
         return True
 
+ParserRuleContext = None
+
 class ParseTreeListener(object):
 
     def visitTerminal(self, node:TerminalNode):