diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 11c85d8..62b5b75 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -7,7 +7,7 @@ on:
 
 jobs:
   pre-build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
 
diff --git a/app/Dockerfile b/app/Dockerfile
index 0c5b748..94b1926 100644
--- a/app/Dockerfile
+++ b/app/Dockerfile
@@ -16,12 +16,12 @@ RUN set -x && \
     apk del --purge .deps
 
 # Required for docker-compose to find zlib.
-ENV LD_LIBRARY_PATH=/lib:/usr/lib
+#ENV LD_LIBRARY_PATH=/lib:/usr/lib
 
-RUN VERSION=v2.27.0 && \
-    DOCKER_COMPOSE_URL=https://github.com/docker/compose/releases/download/${VERSION}/docker-compose-linux-x86_64 && \
-    wget -q -O /usr/local/bin/docker-compose ${DOCKER_COMPOSE_URL} && \
-    chmod a+rx /usr/local/bin/docker-compose
+#RUN VERSION=v2.27.0 && \
+#    DOCKER_COMPOSE_URL=https://github.com/docker/compose/releases/download/${VERSION}/docker-compose-linux-x86_64 && \
+#    wget -q -O /usr/local/bin/docker-compose ${DOCKER_COMPOSE_URL} && \
+#    chmod a+rx /usr/local/bin/docker-compose
 
 # - - - - - - - - - - - - - - - - - - - - - -
 # install commander source
diff --git a/app/server/down.rb b/app/server/down.rb
index b465bb6..a42084d 100644
--- a/app/server/down.rb
+++ b/app/server/down.rb
@@ -6,9 +6,9 @@ def cyber_dojo_server_down
   if docker_swarm?
     system("docker stack down cyber-dojo")
   else
-    # A successful [docker-compose ... down] writes to stderr !?
+    # A successful [docker compose ... down] writes to stderr !?
     # See https://github.com/docker/compose/issues/3267
-    system(down_env_vars, "docker-compose #{docker_yml_files} down --remove-orphans 2>&1")
+    system(down_env_vars, "docker compose #{docker_yml_files} down --remove-orphans 2>&1")
   end
 end
 
diff --git a/app/server/up.rb b/app/server/up.rb
index 3386db9..25116bd 100644
--- a/app/server/up.rb
+++ b/app/server/up.rb
@@ -42,9 +42,9 @@ def cyber_dojo_server_up
     command = "docker stack up #{docker_swarm_yml_files} cyber-dojo"
     system(env_vars, command)
   else
-    command = "docker-compose #{docker_yml_files} up -d --remove-orphans"
+    command = "docker compose #{docker_yml_files} up -d --remove-orphans"
     system(env_vars, "#{command} 2>&1")
-    # A successful [docker-compose ... up] writes to stderr !?
+    # A successful [docker compose ... up] writes to stderr !?
     # See https://github.com/docker/compose/issues/3267
   end
 end