diff --git a/bindings/python/src/PyXRootD.hh b/bindings/python/src/PyXRootD.hh
index dcdacd1a10c..a979186865a 100644
--- a/bindings/python/src/PyXRootD.hh
+++ b/bindings/python/src/PyXRootD.hh
@@ -25,6 +25,7 @@
 #ifndef PYXROOTD_HH_
 #define PYXROOTD_HH_
 
+#define PY_SSIZE_T_CLEAN
 #include <Python.h>
 #include <string>
 #include "structmember.h"