diff --git a/conf/distro/include/tcmode-external-sourcery.inc b/conf/distro/include/tcmode-external-sourcery.inc
index d298f78..cf9bf67 100644
--- a/conf/distro/include/tcmode-external-sourcery.inc
+++ b/conf/distro/include/tcmode-external-sourcery.inc
@@ -239,7 +239,7 @@ SOURCERY_VERSION[vardepvalue] = "${SOURCERY_VERSION}"
 EXTERNAL_PV_SUFFIX ?= "-${SOURCERY_VERSION}"
 EXTERNAL_PV_SUFFIX_allarch = ""
 
-BUILDCFG_VARS += "EXTERNAL_TOOLCHAIN SOURCERY_VERSION GCC_VERSION"
+BUILDCFG_VARS += "EXTERNAL_TOOLCHAIN EXTERNAL_TARGET_SYS SOURCERY_VERSION GCC_VERSION"
 
 # Adjust tunings to ensure we're using Sourcery G++ multilibs
 require conf/distro/include/sourcery-tuning.inc