SerializableDictionary

I use SerializableDictionary without any issues in Unity on PC. When I try to build the app on Android, I get the following error:

The type or namespace name 'SerializableDictionary<,>' could not be found (are you missing a using directive or an assembly reference?)

I am unsure if I must import anything besides the Meta All-In-One SDK to make It work on Android. It works flawlessly on PC.