Add declaration for PyErr_WarnExplicit().
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 7d8ed84..622af2d 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -94,6 +94,8 @@
 
 /* Issue a warning or exception */
 extern DL_IMPORT(int) PyErr_Warn(PyObject *, char *);
+extern DL_IMPORT(int) PyErr_WarnExplicit(PyObject *, char *,
+					 char *, int, char *, PyObject *);
 
 /* In sigcheck.c or signalmodule.c */
 extern DL_IMPORT(int) PyErr_CheckSignals(void);