diff --git a/sdk/mkproject.sh b/sdk/mkproject.sh
index bfc057d42..284cbfbf6 100755
--- a/sdk/mkproject.sh
+++ b/sdk/mkproject.sh
@@ -74,8 +74,8 @@ do_mkproject() {
 		NCPU="$(grep -c processor /proc/cpuinfo)"
 		chmod 644 ${MKP_PROJECTPATH}/conf/bblayers.conf ${MKP_PROJECTPATH}/conf/local.conf
 		sed -i  -e "s,##DIGIBASE##,${MKP_SCRIPTPATH}/sources,g" ${MKP_PROJECTPATH}/conf/bblayers.conf
-		sed -i  -e "/^#BB_NUMBER_THREADS =/cBB_NUMBER_THREADS = \"${NCPU}\"" \
-			-e "/^#PARALLEL_MAKE =/cPARALLEL_MAKE = \"-j ${NCPU}\"" \
+		sed -i  -e "/^#BB_NUMBER_THREADS ?=/cBB_NUMBER_THREADS ?= \"${NCPU}\"" \
+			-e "/^#PARALLEL_MAKE ?=/cPARALLEL_MAKE ?= \"-j ${NCPU}\"" \
 			${MKP_PROJECTPATH}/conf/local.conf
 		if [ -n "${MKP_VARIANT+x}" ]; then
 			sed -i -e "/^MACHINE_VARIANT =/cMACHINE_VARIANT = \"${MKP_VARIANT}\"" \