diff --git a/subjects/btreeapplybylevel/README.md b/subjects/btreeapplybylevel/README.md
index 498540092..c9594c1b3 100644
--- a/subjects/btreeapplybylevel/README.md
+++ b/subjects/btreeapplybylevel/README.md
@@ -2,7 +2,7 @@
 
 ### Instructions
 
-Write a function, `BTreeApplyByLevel`, that applies the function given by `fn` to each node of the tree given by `root`.
+Write a function, `BTreeApplyByLevel`, that applies the function given by `f`, to each node of the tree given by `root`.
 
 ### Expected function