diff --git a/bin/start-slave.sh b/bin/start-slave.sh
index aaf3bc3598153591607abf65b4128c2bcfdddf18..87a074414429c829ae3c2c12afdc5e7979f2e846 100755
--- a/bin/start-slave.sh
+++ b/bin/start-slave.sh
@@ -17,6 +17,6 @@ if [ -f "$f" ]; then
 fi
 
 echo "This jenkins slave.jar will run as PID $$."
-export JAVA_ARGS="-Xms1G -Xmx1G"
+export JAVA_ARGS="-Xmn128M -Xms1G -Xmx1G -client"
 export MALLOC_ARENA_MAX=1
 exec java $JAVA_ARGS -jar /var/lib/jenkins/slave.jar
diff --git a/hosts/jenkins/etc/default/jenkins b/hosts/jenkins/etc/default/jenkins
index 4f70e15894c90680b6761b87accd7bb1af65e1b2..ac5ca966aaa8ed871c3354cada8e589bb4659581 100644
--- a/hosts/jenkins/etc/default/jenkins
+++ b/hosts/jenkins/etc/default/jenkins
@@ -16,7 +16,7 @@ JAVA_ARGS="-Djava.awt.headless=true"
 
 #JAVA_ARGS="-Djava.net.preferIPv4Stack=true" # make jenkins listen on IPv4 address
 # See some recommendation from https://jenkins.io/blog/2016/11/21/gc-tuning/
-JAVA_ARGS="$JAVA_ARGS -Xms24G -Xmx24G"  # heap settings
+JAVA_ARGS="$JAVA_ARGS -Xmn1G -Xms24G -Xmx24G"  # heap settings
 JAVA_ARGS="$JAVA_ARGS -server "
 JAVA_ARGS="$JAVA_ARGS -XX:+AlwaysPreTouch"
 # store heap dumps in case of OOM, to investigate it later