diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c40be66a..b20acdfc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
           --health-timeout 5s
           --health-retries 5
       co_execenv_java:
-        image: openhpi/co_execenv_java:8
+        image: openhpi/co_execenv_java:8-antlr
 
     steps:
       - name: Configure Docker host
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 77c3b3ee..e7fe57cc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -43,7 +43,7 @@ rspec:
     - rake db:schema:load
     - rake db:migrate
     - docker login -u "${DOCKERHUB_USER}" -p "${DOCKERHUB_PASS}"
-    - docker pull openhpi/co_execenv_java:8
+    - docker pull openhpi/co_execenv_java:8-antlr
   script:
     - rspec --format progress
   coverage: '/\(\d+.\d+\%\) covered/'
diff --git a/spec/controllers/execution_environments_controller_spec.rb b/spec/controllers/execution_environments_controller_spec.rb
index 3d4a3896..2e3de1d3 100644
--- a/spec/controllers/execution_environments_controller_spec.rb
+++ b/spec/controllers/execution_environments_controller_spec.rb
@@ -9,6 +9,7 @@ describe ExecutionEnvironmentsController do
   before do
     allow(controller).to receive(:current_user).and_return(user)
     allow(controller).to receive(:sync_to_runner_management).and_return(nil)
+    allow(Runner.strategy_class).to receive(:available_images).and_return([])
   end
 
   describe 'POST #create' do
diff --git a/spec/factories/execution_environment.rb b/spec/factories/execution_environment.rb
index c13c2292..26aa002e 100644
--- a/spec/factories/execution_environment.rb
+++ b/spec/factories/execution_environment.rb
@@ -37,7 +37,7 @@ FactoryBot.define do
     created_by_teacher
     default_memory_limit
     default_cpu_limit
-    docker_image { 'openhpi/co_execenv_java:8' }
+    docker_image { 'openhpi/co_execenv_java:8-antlr' }
     file_type { association :dot_java, user: user }
     help
     name { 'Java 8' }
diff --git a/spec/features/authorization_spec.rb b/spec/features/authorization_spec.rb
index 8200964e..cc8fcb9d 100644
--- a/spec/features/authorization_spec.rb
+++ b/spec/features/authorization_spec.rb
@@ -3,6 +3,8 @@
 require 'rails_helper'
 
 describe 'Authorization' do
+  before { allow(Runner.strategy_class).to receive(:available_images).and_return([]) }
+
   context 'when being an admin' do
     let(:user) { FactoryBot.create(:admin) }
 
diff --git a/spec/lib/docker_client_spec.rb b/spec/lib/docker_client_spec.rb
index 70f56eea..54746d51 100644
--- a/spec/lib/docker_client_spec.rb
+++ b/spec/lib/docker_client_spec.rb
@@ -14,6 +14,8 @@ describe DockerClient do
   let(:workspace_path) { WORKSPACE_PATH }
 
   before do
+    docker_image = Docker::Image.new(Docker::Connection.new('http://example.org', {}), 'id' => SecureRandom.hex, 'RepoTags' => [FactoryBot.attributes_for(:java)[:docker_image]])
+    allow(described_class).to receive(:find_image_by_tag).and_return(docker_image)
     described_class.initialize_environment
     allow(described_class).to receive(:container_creation_options).and_wrap_original do |original_method, *args, &block|
       result = original_method.call(*args, &block)
@@ -69,6 +71,10 @@ describe DockerClient do
   describe '.create_container' do
     let(:create_container) { described_class.create_container(execution_environment) }
 
+    after do
+      FileUtils.rm_rf(workspace_path)
+    end
+
     it 'uses the correct Docker image' do
       expect(described_class).to receive(:find_image_by_tag).with(execution_environment.docker_image).and_call_original
       container = create_container
@@ -425,7 +431,7 @@ describe DockerClient do
 
       it "returns the container's output" do
         expect(send_command[:stderr]).to be_blank
-        expect(send_command[:stdout]).to start_with('root')
+        expect(send_command[:stdout]).to start_with('user')
       end
 
       it 'returns a corresponding status' do