diff --git a/Include/stringobject.h b/Include/stringobject.h
index d9f1840..18b5b41 100644
--- a/Include/stringobject.h
+++ b/Include/stringobject.h
@@ -177,16 +177,26 @@
 				   strings) */
     );
 
+
 /* Using the current locale, insert the thousands grouping
    into the string pointed to by buffer.  For the argument descriptions,
    see Objects/stringlib/localeutil.h */
+PyAPI_FUNC(Py_ssize_t) _PyString_InsertThousandsGroupingLocale(char *buffer,
+                                  Py_ssize_t n_buffer,
+                                  char *digits,
+                                  Py_ssize_t n_digits,
+                                  Py_ssize_t min_width);
 
-PyAPI_FUNC(int) _PyString_InsertThousandsGrouping(char *buffer,
-						  Py_ssize_t n_buffer,
-						  Py_ssize_t n_digits,
-						  Py_ssize_t buf_size,
-						  Py_ssize_t *count,
-						  int append_zero_char);
+/* Using explicit passed-in values, insert the thousands grouping
+   into the string pointed to by buffer.  For the argument descriptions,
+   see Objects/stringlib/localeutil.h */
+PyAPI_FUNC(Py_ssize_t) _PyString_InsertThousandsGrouping(char *buffer,
+                                  Py_ssize_t n_buffer,
+                                  char *digits,
+                                  Py_ssize_t n_digits,
+                                  Py_ssize_t min_width,
+                                  const char *grouping,
+                                  const char *thousands_sep);
 
 /* Format the object based on the format_spec, as defined in PEP 3101
    (Advanced String Formatting). */