diff --git a/ci/cpu/build.sh b/ci/cpu/build.sh
index b99f17b6892..be00187c990 100755
--- a/ci/cpu/build.sh
+++ b/ci/cpu/build.sh
@@ -10,8 +10,9 @@ function logger() {
   echo -e "\n>>>> $@\n"
 }
 
-# Set path
+# Set path and build parallel level
 export PATH=/conda/bin:/usr/local/cuda/bin:$PATH
+export PARALLEL_LEVEL=4
 
 # Set home to the job's workspace
 export HOME=$WORKSPACE