diff --git a/back/Dockerfile b/back/Dockerfile
index b63db51c..a8ce3c1c 100644
--- a/back/Dockerfile
+++ b/back/Dockerfile
@@ -1,11 +1,11 @@
 # protobuf build
-FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d
+FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d as builder
 WORKDIR /usr/src
 COPY messages .
 RUN yarn install && yarn proto
 
 # typescript build
-FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d
+FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d as builder2
 WORKDIR /usr/src
 COPY back/yarn.lock back/package.json ./
 RUN yarn install
diff --git a/pusher/Dockerfile b/pusher/Dockerfile
index 5a448ee8..cd5bfc59 100644
--- a/pusher/Dockerfile
+++ b/pusher/Dockerfile
@@ -1,11 +1,11 @@
 # protobuf build
-FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d
+FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d as builder
 WORKDIR /usr/src
 COPY messages .
 RUN yarn install && yarn proto
 
 # typescript build
-FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d
+FROM node:14.18.2-buster-slim@sha256:20bedf0c09de887379e59a41c04284974f5fb529cf0e13aab613473ce298da3d as builder2
 WORKDIR /usr/src
 COPY pusher/yarn.lock pusher/package.json ./
 RUN yarn install