diff --git a/Dockerfile b/Dockerfile
index 0d7efbe..4f4f533 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,8 @@
 # Portage tree.
-FROM gentoo/portage:latest as portage
+FROM gentoo/portage:latest AS portage
 
 # Base Gentoo image
-FROM gentoo/stage3:amd64-nomultilib-openrc as build
+FROM gentoo/stage3:amd64-nomultilib-openrc AS build
 LABEL maintainer=manuel@fritteli.ch
 LABEL description="Gentoo pkgcheck image"
 
diff --git a/readme.md b/readme.md
index aaea342..d5a1c25 100644
--- a/readme.md
+++ b/readme.md
@@ -1,16 +1,13 @@
 # Build instructions
 
-Run `docker build .` in this directory. After the build succeeds, note the image hash.
-
-
-# Troubleshooting
-
-If you get any error during the build, try pulling the required base images prior to building:
+Update dependent images:
 ```commandline
 docker image pull gentoo/portage:latest
 docker image pull gentoo/stage3:amd64-nomultilib-openrc
 ```
 
+Run `docker build .` in this directory. After the build succeeds, note the image hash.
+
 # Publishing
 Tag the built image with the current date as the name:
 ```commandline