diff --git a/util/genbuild_h/genbuild_h.sh b/util/genbuild_h/genbuild_h.sh
index bafdbc95d7..c264b74635 100755
--- a/util/genbuild_h/genbuild_h.sh
+++ b/util/genbuild_h/genbuild_h.sh
@@ -52,6 +52,9 @@ NetBSD|OpenBSD|DragonFly|FreeBSD|Darwin)
 esac
 }
 
+IASL=util/crossgcc/xgcc/bin/iasl
+eval $(grep ^IASL:= .xcompile 2>/dev/null | sed s,:=,=,)
+
 #Print out the information that goes into build.h
 printf "/* build system definitions (autogenerated) */\n"
 printf "#ifndef __BUILD_H\n"
@@ -73,5 +76,5 @@ printf "#define COREBOOT_BUILD_WEEKDAY_BCD 0x$(our_date "$DATE" +%w)\n"
 printf "#define COREBOOT_DMI_DATE \"$(our_date "$DATE" +%m/%d/%Y)\"\n"
 printf "\n"
 printf "#define COREBOOT_COMPILE_TIME \"$(our_date "$DATE" +%T)\"\n"
-printf "#define ASL_VERSION 0x%d\n" `./util/crossgcc/xgcc/bin/iasl -v | grep version | sed 's/.*version //'`
+printf "#define ASL_VERSION 0x%d\n" `$IASL -v | grep version | sed 's/.*version //'`
 printf "#endif\n"