diff --git a/lib/docker_client.rb b/lib/docker_client.rb
index 3b39c71b..3927fe9f 100644
--- a/lib/docker_client.rb
+++ b/lib/docker_client.rb
@@ -198,7 +198,7 @@ class DockerClient
     execute_websocket_command(command, create_workspace_files, block)
   end
 
-  def execute_test_command(subbmission, filename, &block)
+  def execute_test_command(submission, filename, &block)
     """
     Stick to existing Docker API with exec command.
     """