diff --git a/ci/build.sh b/ci/build.sh
index 17d075b..99ae979 100755
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -6,6 +6,7 @@
 ZUUL_JOB_NAME=$(jq < ~/zuul-env.json -r '.job')
 ZUUL_PROJECT_SRC_DIR=$HOME/$(jq < ~/zuul-env.json -r '.project.src_dir')
 ZUUL_PROJECT_SHORT_NAME=$(jq < ~/zuul-env.json -r '.project.short_name')
+CI_PARALLEL_JOBS=$(grep -c '^processor' /proc/cpuinfo)
 
 BUILD_DIR=~/build
 mkdir ${BUILD_DIR}
@@ -23,7 +24,8 @@
 echo BR2_PRIMARY_SITE=\"https://ci-logs.gerrit.cesnet.cz/t/public/mirror/buildroot\" >> .config
 make source
 
-make
+sed -i 's/^\(\.NOTPARALLEL\).*/#\1/' ${ZUUL_PROJECT_SRC_DIR}/submodules/buildroot/Makefile
+make -j${CI_PARALLEL_JOBS}
 mv images/update.raucb ~/zuul-output/artifacts/
 
 if [[ "${ZUUL_JOB_NAME}" =~ clearfog ]]; then
diff --git a/submodules/buildroot b/submodules/buildroot
index d7ba25b..e5b1510 160000
--- a/submodules/buildroot
+++ b/submodules/buildroot
@@ -1 +1 @@
-Subproject commit d7ba25b4b749ae3aa6665f4b289179067a2eb6e2
+Subproject commit e5b1510a81bda096dacc133276f1ff2643131dcc