diff --git a/.buildbot/openwrt/build.sh b/.buildbot/openwrt/build.sh
index c6ec449..89e73e3 100755
--- a/.buildbot/openwrt/build.sh
+++ b/.buildbot/openwrt/build.sh
@@ -41,8 +41,8 @@ echo "CONFIG_KERNEL_NVME_HWMON=y" >> .config
 echo "CONFIG_KERNEL_NVME_MULTIPATH=n" >> .config
 
 # Kernel modules
-make target/linux/clean
-make target/linux/prepare
+make -j1 -Vs target/linux/clean
+make -j1 -Vs target/linux/prepare
 make target/linux
 
 ${MAKE} package/i2c-tools/compile