--- .//mono/mini/Makefile.in.orig	2015-03-06 10:48:11.000000000 -0700
+++ .//mono/mini/Makefile.in	2015-10-03 11:21:26.000000000 -0700
@@ -2915,7 +2915,7 @@
 
 iltests.il: iltests.il.in Makefile.am
 	echo '// DO NOT EDIT: This file has been generated from iltests.il.in' > iltests.il
-	cpp -Darch=$(arch_define) < $(srcdir)/iltests.il.in | sed 's/^#.*//' >> iltests.il
+	$(CPP) -Darch=$(arch_define) < $(srcdir)/iltests.il.in - | sed 's/^#.*//' >> iltests.il
 
 %.exe: %.il
 	$(ILASM) -output=$@ $<