diff --git a/docker/shared_testnet/README.md b/docker/shared_testnet/README.md
index d8bcf93d2..23197e955 100644
--- a/docker/shared_testnet/README.md
+++ b/docker/shared_testnet/README.md
@@ -26,7 +26,7 @@ git pull
 ansible-galaxy install -g -f -r ansible/requirements.yml
 ansible-playbook ansible/nimbus.yml -i ansible/inventory/test -t beacon-node -u YOUR_USER -K -l nimbus-slaves[5:8]
 
-# faster way to pull the Docker image and recreate the containers
+# faster way to pull the Docker image and recreate the containers (this also stops any running container)
 ansible nimbus-slaves[5:8] -i ansible/inventory/test -u YOUR_USER -o -m shell -a "echo; cd /docker/beacon-node-testnet2-1; docker-compose --compatibility pull; docker-compose --compatibility up --no-start; echo '---'" | sed 's/\\n/\n/g'
 
 # build beacon_node in an external volume
diff --git a/docker/shared_testnet/entry_point.sh b/docker/shared_testnet/entry_point.sh
index 293464f42..e11bf9dc6 100755
--- a/docker/shared_testnet/entry_point.sh
+++ b/docker/shared_testnet/entry_point.sh
@@ -82,8 +82,9 @@ if [[ "$BUILD" == "1" ]]; then
   git config pull.rebase false
   git checkout devel
   git pull
-  make -j$(nproc) update
-  make LOG_LEVEL="TRACE" NIMFLAGS="-d:insecure -d:testnet_servers_image" SCRIPT_PARAMS="--skipGoerliKey --writeLogFile=false --buildOnly" ${NETWORK}
+  # don't use too much RAM
+  make update
+  make LOG_LEVEL="TRACE" NIMFLAGS="-d:insecure -d:testnet_servers_image --parallelBuild:1" SCRIPT_PARAMS="--skipGoerliKey --writeLogFile=false --buildOnly" ${NETWORK}
 fi
 
 #######