Codecademy Meal Maker

I cant seem to find whats wrong with my code . Please Help.
It says.
/home/ccuser/workspace/learn-javascript-objects-meal-maker/app.js:37
return this._courses[courseName].push(dish);
^

TypeError: Cannot read property ‘push’ of undefined
at Object.addDishToCourse (/home/ccuser/workspace/learn-javascript-objects-meal-maker/app.js:37:35)
at Object. (/home/ccuser/workspace/learn-javascript-objects-meal-maker/app.js:56:6)
at Module._compile (module.js:571:32)
at Object.Module._extensions…js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.runMain (module.js:605:10)
at run (bootstrap_node.js:427:7)
at startup (bootstrap_node.js:151:9)

Hi there, and welcome to the forums!

There’s a couple small issues here that are affecting your code output, but they’re very small and easy to miss. Check everywhere that you have entered “main”, as these should be “mains” based on your naming scheme. Same with “appetizer”, these should actually be “appetizers” so double check that. I believe if you fix all those typos that should fix your code.