--- Makefile	2014-05-21 09:21:43.000000000 -0400
+++ Makefile	2014-10-06 23:28:09.000000000 -0400
@@ -96,7 +96,7 @@
 	                                              /usr/local/include))
 endif
 
-ALL_CPPFLAGS += $(CPPFLAGS)
+ALL_CPPFLAGS += $(CPPFLAGS) @CPPFLAGS@
 
 #------------------------------------------------------------------------------
 # HMD handling is a complicated with 6 platform-backend combinations.