diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 668d6e4..f6996c7 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -36,6 +36,7 @@
 
 */
 
+#define PY_SSIZE_T_CLEAN
 #include "Python.h"
 
 #include "unicodeobject.h"