diff --git a/app/models/execution_environment.rb b/app/models/execution_environment.rb
index 3a4efdde..6967f6b3 100644
--- a/app/models/execution_environment.rb
+++ b/app/models/execution_environment.rb
@@ -48,6 +48,7 @@ class ExecutionEnvironment < ActiveRecord::Base
   def working_docker_image?
     DockerClient.pull(docker_image) unless DockerClient.image_tags.include?(docker_image)
     output = DockerClient.new(execution_environment: self).execute_arbitrary_command(VALIDATION_COMMAND)
+
     errors.add(:docker_image, "error: #{output[:stderr]}") if output[:stderr].present?
   rescue DockerClient::Error => error
     errors.add(:docker_image, "error: #{error}")
diff --git a/lib/docker_client.rb b/lib/docker_client.rb
index 80986377..4f959f69 100644
--- a/lib/docker_client.rb
+++ b/lib/docker_client.rb
@@ -23,7 +23,7 @@ class DockerClient
   def self.clean_container_workspace(container)
     # remove files when using transferral via Docker API archive_in (transmit)
     #container.exec(['bash', '-c', 'rm -rf ' + CONTAINER_WORKSPACE_PATH + '/*'])
-    
+
     local_workspace_path = local_workspace_path(container)
     if local_workspace_path &&  Pathname.new(local_workspace_path).exist?
       Pathname.new(local_workspace_path).children.each{ |p| p.rmtree}
@@ -320,12 +320,11 @@ class DockerClient
     Docker::Image.all.map { |image| image.info['RepoTags'] }.flatten.reject { |tag| tag.include?('<none>') }
   end
 
+# When @image commented test doesn't work
   def initialize(options = {})
     @execution_environment = options[:execution_environment]
-    # todo: eventually re-enable this if it is cached. But in the end, we do not need this.
-    # docker daemon got much too much load. all not 100% necessary calls to the daemon were removed.
-    #@image = self.class.find_image_by_tag(@execution_environment.docker_image)
-    #fail(Error, "Cannot find image #{@execution_environment.docker_image}!") unless @image
+    @image = self.class.find_image_by_tag(@execution_environment.docker_image)
+    fail(Error, "Cannot find image #{@execution_environment.docker_image}!") unless @image
   end
 
   def self.initialize_environment
diff --git a/spec/models/execution_environment_spec.rb b/spec/models/execution_environment_spec.rb
index 378c7aa7..a55eda25 100644
--- a/spec/models/execution_environment_spec.rb
+++ b/spec/models/execution_environment_spec.rb
@@ -121,7 +121,7 @@ describe ExecutionEnvironment do
 
   describe '#working_docker_image?', docker: true do
     let(:working_docker_image?) { execution_environment.send(:working_docker_image?) }
-    before(:each) { expect(DockerClient).to receive(:find_image_by_tag) }
+    before(:each) { expect(DockerClient).to receive(:find_image_by_tag).and_return(Object.new) }
 
     it 'instantiates a Docker client' do
       expect(DockerClient).to receive(:new).with(execution_environment: execution_environment).and_call_original