diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..4469528
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1 @@
+**/build
diff --git a/Dockerfile b/Dockerfile
index be5cb87..846fda1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:latest
+FROM ubuntu:20.04
 
 RUN set -e && \
     apt-get update -q -y --no-install-recommends && \
@@ -24,7 +24,7 @@ RUN git submodule update --init --recursive && \
 
 # ---
 
-FROM ubuntu:latest
+FROM ubuntu:20.04
 COPY --from=0 /usr/src/p2pool/build/p2pool /
 
 RUN set -e && \
@@ -43,6 +43,7 @@ USER p2pool
 
 EXPOSE 3333
 EXPOSE 37889
+EXPOSE 37888
 
 VOLUME /home/p2pool/.p2pool
 
diff --git a/docker-compose/README.md b/docker-compose/README.md
index f5a1fa4..9fa797a 100644
--- a/docker-compose/README.md
+++ b/docker-compose/README.md
@@ -46,7 +46,7 @@ docker-compose up
 
 
 #### Uninstall
-Change to p2pool/docker-compose directory
-Stop and remove all containers: ```docker-compose down```
-Remove the p2pool data: ```docker volume rm p2pool```
+Change to p2pool/docker-compose directory <br />
+Stop and remove all containers: ```docker-compose down``` <br />
+Remove the p2pool data: ```docker volume rm p2pool``` <br />
 Remove the monero data: ```docker volume rm monero```
diff --git a/docker-compose/monero/Dockerfile b/docker-compose/monero/Dockerfile
index ce932a6..1bfc4d1 100644
--- a/docker-compose/monero/Dockerfile
+++ b/docker-compose/monero/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:latest
+FROM ubuntu:20.04
 ARG MONERO_GIT_TAG="latest"
 
 RUN set -e && \
@@ -54,7 +54,7 @@ RUN git clone --recursive https://github.com/monero-project/monero && \
 
 # ---
 
-FROM ubuntu:latest
+FROM ubuntu:20.04
 
 COPY --from=0 /usr/src/monero/build/Linux/*/release/bin/* /
 
diff --git a/docker-compose/xmrig/Dockerfile b/docker-compose/xmrig/Dockerfile
index 5af34f6..d1b05a4 100644
--- a/docker-compose/xmrig/Dockerfile
+++ b/docker-compose/xmrig/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:latest
+FROM ubuntu:20.04
 
 RUN set -e && \
     apt-get update -q -y --no-install-recommends && \
@@ -20,7 +20,7 @@ RUN git clone https://github.com/xmrig/xmrig.git && \
 
 # ---
 
-FROM ubuntu:latest
+FROM ubuntu:20.04
 
 COPY --from=0 /usr/src/xmrig/build/xmrig /