diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 52a36d788b..e88dc2b5bf 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -389,6 +389,7 @@ FILESYSTEM_PERMS_TABLES ?= "${@'files/fs-perms.txt' if oe.types.boolean(d.getVar
 
 TCMODE ??= "default"
 TCLIBC ??= "glibc"
+TCXXRUNTIME ??= "gnu"
 TMPDIR ?= "${TOPDIR}/tmp"
 
 CACHE = "${TMPDIR}/cache/${TCMODE}-${TCLIBC}${@['', '/' + str(d.getVar('MACHINE'))][bool(d.getVar('MACHINE'))]}${@['', '/' + str(d.getVar('SDKMACHINE'))][bool(d.getVar('SDKMACHINE'))]}"