diff --git a/Makefile.core-AM_CPPFLAGS.am b/Makefile.core-AM_CPPFLAGS.am
index 736bb22..a0b4578 100644
--- a/Makefile.core-AM_CPPFLAGS.am
+++ b/Makefile.core-AM_CPPFLAGS.am
@@ -8,7 +8,10 @@
 		-I$(top_srcdir)/include/$(VG_ARCH) \
 		-I$(top_srcdir)/include/$(VG_OS) \
 		-I$(top_srcdir)/include/$(VG_PLATFORM) \
-		-I@VEX_DIR@/pub
+		-I@VEX_DIR@/pub \
+		-DVGA_$(VG_ARCH)=1 \
+		-DVGO_$(VG_OS)=1 \
+		-DVGP_$(VG_ARCH)_$(VG_OS)=1
 
 AM_CPPFLAGS = $(add_includes)
 AM_CCASFLAGS = $(add_includes) @ARCH_CORE_AM_CCASFLAGS@ -Wa,-gstabs