diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 370ac41..3aee28e 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -570,6 +570,8 @@
 #include "stringlib/ctype.h"
 #include "stringlib/transmogrify.h"
 
+#define _Py_InsertThousandsGrouping _PyString_InsertThousandsGrouping
+#include "stringlib/localeutil.h"
 
 PyObject *
 PyString_Repr(PyObject *obj, int smartquotes)