diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 6d4c1a2af..116b439f1 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -25,6 +25,6 @@ RUN curl https://packages.microsoft.com/keys/microsoft.asc | sudo tee /etc/apt/t
 RUN mkdir -p /tmp/activerecord-sqlserver-adapter
 COPY Gemfile VERSION activerecord-sqlserver-adapter.gemspec /tmp/activerecord-sqlserver-adapter/
 RUN cd /tmp/activerecord-sqlserver-adapter \
-    && RAILS_BRANCH=main bundle install \
+    && bundle install \
     && rm -rf /tmp/activerecord-sqlserver-adapter
 RUN chown -R vscode:vscode /usr/local/rvm
diff --git a/Dockerfile.ci b/Dockerfile.ci
index 74f636508..0ded95afd 100644
--- a/Dockerfile.ci
+++ b/Dockerfile.ci
@@ -9,6 +9,6 @@ WORKDIR $WORKDIR
 
 COPY . $WORKDIR
 
-RUN RAILS_BRANCH=main bundle install --jobs `expr $(cat /proc/cpuinfo | grep -c "cpu cores") - 1` --retry 3
+RUN bundle install --jobs `expr $(cat /proc/cpuinfo | grep -c "cpu cores") - 1` --retry 3
 
 CMD ["sh"]
diff --git a/docker-compose.ci.yml b/docker-compose.ci.yml
index f339681e7..cbc842619 100644
--- a/docker-compose.ci.yml
+++ b/docker-compose.ci.yml
@@ -5,7 +5,6 @@ services:
   ci:
     environment:
       - ACTIVERECORD_UNITTEST_HOST=sqlserver
-      - RAILS_BRANCH=main
     build:
       context: .
       dockerfile: Dockerfile.ci