diff --git a/substrate/.maintain/docker/subkey.Dockerfile b/substrate/.maintain/docker/subkey.Dockerfile
index 9184cad5b4..5797295806 100644
--- a/substrate/.maintain/docker/subkey.Dockerfile
+++ b/substrate/.maintain/docker/subkey.Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:stretch-slim
+FROM docker.io/library/ubuntu:20.04
 
 # metadata
 ARG VCS_REF
@@ -28,4 +28,3 @@ USER subkey
 RUN /usr/local/bin/subkey --version
 
 ENTRYPOINT ["/usr/local/bin/subkey"]
-
diff --git a/substrate/.maintain/docker/substrate.Dockerfile b/substrate/.maintain/docker/substrate.Dockerfile
index 7cd4576a9e..e13dfb426a 100644
--- a/substrate/.maintain/docker/substrate.Dockerfile
+++ b/substrate/.maintain/docker/substrate.Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:stretch-slim
+FROM docker.io/library/ubuntu:20.04
 
 # metadata
 ARG VCS_REF
@@ -42,4 +42,3 @@ EXPOSE 30333 9933 9944
 VOLUME ["/substrate"]
 
 ENTRYPOINT ["/usr/local/bin/substrate"]
-
diff --git a/substrate/README.md b/substrate/README.md
index 1ccebac908..6288540548 100644
--- a/substrate/README.md
+++ b/substrate/README.md
@@ -4,13 +4,12 @@
   <img src="/docs/media/sub.gif">
 </p>
 
-
 Substrate is a next-generation framework for blockchain innovation 🚀.
 
 ## Trying it out
 
-Simply go to [substrate.dev](https://substrate.dev) and follow the 
-[installation](https://substrate.dev/docs/en/knowledgebase/getting-started/) instructions. You can 
+Simply go to [substrate.dev](https://substrate.dev) and follow the
+[installation](https://substrate.dev/docs/en/knowledgebase/getting-started/) instructions. You can
 also try out one of the [tutorials](https://substrate.dev/en/tutorials).
 
 ## Contributions & Code of Conduct