diff --git a/free-programming-books-es.md b/free-programming-books-es.md
index 6865185e4..bd9eedc4c 100644
--- a/free-programming-books-es.md
+++ b/free-programming-books-es.md
@@ -37,7 +37,7 @@
 * [Python](#python)
   * [Django](#django)
   * [Web2py](#web2py)
-* [R](#R)
+* [R](#r)
 * [Ruby](#ruby)
   * [Ruby on Rails](#ruby-on-rails)
 * [Scala](#scala)