diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 10f2458..8f85f1d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,8 +14,6 @@ jobs:
 
     # Define environment variables that will be available to all steps within this job.
     env:
-      MONGO_HOST: mongo
-      MONGO_PORT: 27017
       MONGO_USERNAME: admin
       MONGO_PASSWORD: root
       MONGO_DATABASE: bertron
diff --git a/docker-compose.yml b/docker-compose.yml
index 2da64b5..099536c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -9,8 +9,8 @@ services:
     #       host environment.
     # Docs: https://docs.docker.com/compose/how-tos/environment-variables/variable-interpolation/#additional-information
     environment:
-      MONGO_HOST: ${MONGO_HOST:?}
-      MONGO_PORT: ${MONGO_PORT:?}
+      MONGO_HOST: mongo
+      MONGO_PORT: 27017
       MONGO_USERNAME: ${MONGO_USERNAME:?}
       MONGO_PASSWORD: ${MONGO_PASSWORD:?}
       MONGO_DATABASE: ${MONGO_DATABASE:?}
@@ -65,8 +65,8 @@ services:
     # This service should not start automatically - only run on demand
     profiles: ["tools"]
     environment:
-      MONGO_HOST: ${MONGO_HOST:?}
-      MONGO_PORT: ${MONGO_PORT:?}
+      MONGO_HOST: mongo
+      MONGO_PORT: 27017
       MONGO_USERNAME: ${MONGO_USERNAME:?}
       MONGO_PASSWORD: ${MONGO_PASSWORD:?}
       MONGO_DATABASE: ${MONGO_DATABASE:?}  # the test suite will disregard this