diff --git a/01-tree_successor/task.md b/01-tree_successor/task.md
index 4b11338d520a6a5f55552111340e39c7f8ec9890..79e8b78090279ca6384e8a68402457482df31e62 100644
--- a/01-tree_successor/task.md
+++ b/01-tree_successor/task.md
@@ -7,4 +7,4 @@ and it should return another node of the tree with the next higher key
 - The given node can also be a null pointer, in which case the method should
   return the smallest node in the tree.
 
-You should submit the file `tree_successor.h`.
+You should submit the file `tree_successor.*`.