diff --git a/Makefile.tool-tests.am b/Makefile.tool-tests.am
index a9d3b9100..79110dfd3 100644
--- a/Makefile.tool-tests.am
+++ b/Makefile.tool-tests.am
@@ -5,9 +5,10 @@ include $(top_srcdir)/Makefile.all.am
 AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/include \
 		-I$(top_srcdir)/coregrind -I$(top_builddir)/include \
 		-I$(top_srcdir)/VEX/pub \
-		-DVGA_$(VGCONF_ARCH_PRI)=1 \
-		-DVGO_$(VGCONF_OS)=1 \
-		-DVGP_$(VGCONF_ARCH_PRI)_$(VGCONF_OS)=1
+		-DVGA_@VGCONF_ARCH_PRI@=1 \
+		-DVGO_@VGCONF_OS@=1 \
+		-DVGP_@VGCONF_ARCH_PRI@_@VGCONF_OS@=1 \
+		-DVGPV_@VGCONF_ARCH_PRI@_@VGCONF_OS@_@VGCONF_PLATVARIANT@=1
 # Nb: Tools need to augment these flags with an arch-selection option, such
 # as $(AM_FLAG_M3264_PRI).
 AM_CFLAGS   = -Winline -Wall -Wshadow -g