diff --git a/Dockerfile b/Dockerfile
index 61330bb..ede5e62 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,9 +9,12 @@ RUN cd /src/goproxy &&\
 
 FROM golang:alpine
 
+ARG ARCH=amd64
+
 # Add tini
 ENV TINI_VERSION v0.19.0
-ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini-static-amd64 /usr/bin/tini
+ENV TINI_ARCH=$ARCH
+ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini-static-${TINI_ARCH} /usr/bin/tini
 RUN chmod +x /usr/bin/tini
 
 RUN apk add --no-cache -U git mercurial subversion
diff --git a/README.md b/README.md
index 8a99d00..2a6609d 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,20 @@ git config --global url."https://${GITHUB_PERSONAL_ACCESS_TOKEN}@github.com/".in
 
 This can be done for other git providers as well, following the same pattern
 
+## Build docker image
+
+If you want to build the docker image locally (you don't have to):
+
+```shell
+docker build -t goproxy/goproxy:latest .
+```
+
+or if you are running on arm64
+
+```shell
+docker build --build-arg ARCH=arm64 -t goproxy/goproxy:latest .
+```
+
 ## Use docker image
 
 ```shell