diff --git a/_toc.yml b/_toc.yml
index f1ff895c335d69aec8243e9ca02624908629b0c3..ddb13a3810fe889fa42b355d35f7e57084965fff 100644
--- a/_toc.yml
+++ b/_toc.yml
@@ -1,5 +1,5 @@
 format: jb-book
-root: Readme
+root: README
 chapters:
 - file: 01-Python_essentials
 - file: 02-Images_as_arrays