diff --git a/tatsu/contexts.py b/tatsu/contexts.py
index e1c8959a..556db13c 100644
--- a/tatsu/contexts.py
+++ b/tatsu/contexts.py
@@ -569,7 +569,7 @@ def rule(self):
 
     @property
     def memokey(self):
-        self.tokenizer.eat_whitespace()
+        self.tokenizer.next_token()
         return MemoKey(self._pos, self.rule, self.substate)
 
     def _memoize(self, key, memo):