diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index 6b06dec..c24d840 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -60,7 +60,7 @@
          | GeneratorExp(expr elt, comprehension* generators)
          -- the grammar constrains where yield expressions can occur
          | Yield(expr? value)
-             | YieldFrom(expr? value)
+         | YieldFrom(expr value)
          -- need sequences for compare to distinguish between
          -- x < 4 < 3 and (x < 4) < 3
          | Compare(expr left, cmpop* ops, expr* comparators)