diff --git a/samples/java-protobuf-tracing/.env b/samples/java-protobuf-tracing/.env
index 73b8885d27..dcdc6f9863 100644
--- a/samples/java-protobuf-tracing/.env
+++ b/samples/java-protobuf-tracing/.env
@@ -1,2 +1,11 @@
-USER_SERVICE_HOST=host.docker.internal
+# this is the port where the kalix runtime container will be exposed
+# when running multiple services on your local machine, make sure that this port is unique
+ADVERTISED_HTTP_PORT=9000
+
+# this is the port where the user services (your application) will open
+# when running multiple services on your local machine, make sure that this port is unique
 USER_SERVICE_PORT=8080
+
+# this variable defines the host where the kalix runtime (running in docker)
+# will reach the user service in local development
+USER_SERVICE_HOST=host.docker.internal
diff --git a/samples/java-protobuf-tracing/docker-compose.yml b/samples/java-protobuf-tracing/docker-compose.yml
index 62442417f5..d7311653a8 100644
--- a/samples/java-protobuf-tracing/docker-compose.yml
+++ b/samples/java-protobuf-tracing/docker-compose.yml
@@ -8,17 +8,16 @@ services:
     image: gcr.io/kalix-public/kalix-runtime:1.1.34
     container_name: tracing
     ports:
-      - "9000:9000"
+      - "${ADVERTISED_HTTP_PORT}:9000"
     extra_hosts:
       - "host.docker.internal:host-gateway"
     environment:
       JAVA_TOOL_OPTIONS: >
         -Dkalix.proxy.telemetry.tracing.enabled=true
         -Dkalix.proxy.telemetry.tracing.collector-endpoint=http://jaeger:4317
+      ADVERTISED_HTTP_PORT: ${ADVERTISED_HTTP_PORT}
       USER_SERVICE_HOST: ${USER_SERVICE_HOST}
       USER_SERVICE_PORT: ${USER_SERVICE_PORT}
-      # Comment to enable ACL check in dev-mode (see https://docs.kalix.io/services/using-acls.html#_local_development_with_acls)
-      ACL_ENABLED: "false"
   jaeger:
     image: jaegertracing/all-in-one:1.54
     ports: