diff --git a/build.sh b/build.sh
index 7f937d59712bf624a0dc1b847f425d9987019952..f5415208451df518154650a9034840d8517d7df8 100644
--- a/build.sh
+++ b/build.sh
@@ -14,7 +14,7 @@ CURRENT_DIR=$(dirname $(readlink -f ${BASH_SOURCE[0]}))
 BUILD_DIR=${CURRENT_DIR}/build
 OUTPUT_DIR=${CURRENT_DIR}/output
 USER_ID=$(id -u)
-CPU_NUM=$(($(cat /proc/cpuinfo | grep "^processor" | wc -l)*2))
+CPU_NUM=$(($(cat /proc/cpuinfo | grep "^processor" | wc -l)))
 JOB_NUM="-j${CPU_NUM}"
 ASAN="false"
 COV="false"