diff --git a/Include/pytime.h b/Include/pytime.h
index 1f14d6d..bf237c8 100644
--- a/Include/pytime.h
+++ b/Include/pytime.h
@@ -69,12 +69,18 @@
 /* Create a timestamp from a number of nanoseconds (C long). */
 PyAPI_FUNC(_PyTime_t) _PyTime_FromNanoseconds(PY_LONG_LONG ns);
 
-/* Convert a Python float or int to a timetamp.
+/* Convert a number of seconds (Python float or int) to a timetamp.
    Raise an exception and return -1 on error, return 0 on success. */
 PyAPI_FUNC(int) _PyTime_FromSecondsObject(_PyTime_t *t,
     PyObject *obj,
     _PyTime_round_t round);
 
+/* Convert a number of milliseconds (Python float or int, 10^-3) to a timetamp.
+   Raise an exception and return -1 on error, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_FromMillisecondsObject(_PyTime_t *t,
+    PyObject *obj,
+    _PyTime_round_t round);
+
 /* Convert a timestamp to a number of seconds as a C double. */
 PyAPI_FUNC(double) _PyTime_AsSecondsDouble(_PyTime_t t);