Index: Makefile.pre.in
--- Makefile.pre.in.orig
+++ Makefile.pre.in
@@ -1161,7 +1161,7 @@ libinstall:	build_all $(srcdir)/Lib/$(PLATDIR) $(srcdi
 		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/PatternGrammar.txt
 
 # Create the PLATDIR source directory, if one wasn't distributed..
-$(srcdir)/Lib/$(PLATDIR):
+$(srcdir)/Lib/$(PLATDIR): pybuilddir.txt
 	mkdir $(srcdir)/Lib/$(PLATDIR)
 	cp $(srcdir)/Lib/plat-generic/regen $(srcdir)/Lib/$(PLATDIR)/regen
 	export PATH; PATH="`pwd`:$$PATH"; \