diff --git a/3-JSKata/README.md b/3-JSKata/README.md
index abd1dd378..10295b758 100644
--- a/3-JSKata/README.md
+++ b/3-JSKata/README.md
@@ -84,7 +84,7 @@ If things aren't working as you are expecting, `console.log` out the variables a
 
 - [x] [Object and arrays](./1-objects-and-arrays/README.md) (2hrs)
 - [x] [Strings and numbers](./2-strings-and-numbers/README.md) (2hrs)
-- [ ] [Data structures](./3-data-structures/README.md) (2hrs)
+- [x] [Data structures](./3-data-structures/README.md) (2hrs)
 - [ ] [Types](./4-types/README.md) (2hrs)
 
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