Add reindent target.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 91d4849..b1cf8c2 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -956,6 +956,10 @@
 .c.o:
 	$(CC) -c $(PY_CFLAGS) -o $@ $<
 
+# Run reindent on the library
+reindent:
+	./python$(EXEEXT) $(srcdir)/Tools/scripts/reindent.py -r $(srcdir)/Lib
+
 # Rerun configure with the same options as it was run last time,
 # provided the config.status script exists
 recheck: