diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 75241fe..d434d50 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -4,6 +4,8 @@
 #include "Python.h"
 
 #include "Python-ast.h"
+#undef Yield /* to avoid conflict with winbase.h */
+
 #include "grammar.h"
 #include "node.h"
 #include "token.h"