diff --git a/Dockerfile b/Dockerfile
index 583bd59..f9a2934 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.17.0-alpine3.14 as builder
+FROM golang:1.20.4-alpine3.17 as builder
 
 WORKDIR /src
 
diff --git a/README.md b/README.md
index 7fa3c2b..e3e9427 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,6 @@ Then you setup [sentry issue alerts](https://docs.sentry.io/product/alerts/) as
 ### Requirement
 
 - `docker`
-- `go`
 - `bash`
 
 ## Hack
@@ -36,13 +35,15 @@ $ ./scripts/up.sh
 
 This will launch images in [`docker-compose.yml`](./docker-compose.yml).
 
-An image named `workspace` with golang is used as a isolated container to develop. You can use [`enter-workspace.sh`](./scripts/enter-workspace.sh) to enter inside it:
+An image named `workspace` with golang is used as a isolated container to
+develop. You can use [`enter-workspace.sh`](./scripts/enter-workspace.sh)
+to enter inside it:
 
 ```sh
 $ ./scripts/enter-workspace.sh
 ```
 
-You can build with:
+From outside the container you can build with:
 
 ```sh
 $ ./scripts/build.sh
diff --git a/docker-compose.yml b/docker-compose.yml
index 919da1c..47751ba 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,7 +1,7 @@
 version: '3.9'
 services:
   workspace:
-    image: golang:1.17.0-alpine3.14
+    image: golang:1.20.4-alpine3.17
     restart: unless-stopped
     working_dir: /code/
     volumes: