diff --git a/.buildbot/openwrt/build.sh b/.buildbot/openwrt/build.sh
index 1a32dbe..60c1996 100755
--- a/.buildbot/openwrt/build.sh
+++ b/.buildbot/openwrt/build.sh
@@ -11,6 +11,9 @@
 
 set -x
 
+renice -n 19 $$
+export MAKEOPTS="-j $(nproc)"  # FIXME: not sure why export
+
 tar -xJf /Downloads/openwrt-sdk-${OPENWRT_VERSION}-*.tar.xz
 
 cp -r feed openwrt-sdk-*/
@@ -41,7 +44,7 @@ make defconfig
 echo "CONFIG_PACKAGE_COLLECTD_ENCRYPTED_NETWORK=y" >> .config
 
 make package/i2c-tools/compile
-make package/kernel-custom/compile
+make $MAKEOPTS package/kernel-custom/compile
 make package/kmod-i2c-mux-pinctrl/compile
 make package/kmod-rtc-pcf85063/compile
 make package/nvme-cli/compile