diff --git a/API-Docs.md b/API-Docs.md
index 5bf3361..20077df 100644
--- a/API-Docs.md
+++ b/API-Docs.md
@@ -18,7 +18,7 @@ ________________________________________________________________________________
   videoID: string,
   category: string, // Optional, defaults to "sponsor". See [the category list](https://raw.githubusercontent.com/ajayyy/SponsorBlock/master/config.json.example)
   
-  categories: string[] // Use instead of "category" if you want multiple categories. Will look like ["sponsor","intro"]
+  categories: string[] // Optional. Use instead of "category" if you want multiple categories. Will look like ["sponsor","intro"]
 }
 ```