diff --git a/readme.md b/readme.md
index 53c963a..63ef790 100644
--- a/readme.md
+++ b/readme.md
@@ -90,7 +90,7 @@ arrayToTree(data, {
 
 ## API
 
-### `arrayToTree(options)`
+### `arrayToTree(data, options)`
 Convert a plain array of nodes (with pointers to parent nodes) to a a nested data structure.
 
 #### Params