The opcode YIELD_STMT was accidentally called YIELD_VALUE here.
diff --git a/Lib/dis.py b/Lib/dis.py
index 8ea6d98..1529222 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -228,7 +228,7 @@
 def_op('RETURN_VALUE', 83)
 def_op('IMPORT_STAR', 84)
 def_op('EXEC_STMT', 85)
-def_op('YIELD_STMT', 86)
+def_op('YIELD_VALUE', 86)
 
 def_op('POP_BLOCK', 87)
 def_op('END_FINALLY', 88)