diff --git a/free-programming-books-de.md b/free-programming-books-de.md
index 82988dd09..411ceeb4f 100644
--- a/free-programming-books-de.md
+++ b/free-programming-books-de.md
@@ -3,8 +3,8 @@
 * [iOS](#ios)
 * [Java](#java)
 * [Python](#python)
-* [Ruby on Rails](#ruby_on_rails)
-* [Visual Basic](#visual_basic)
+* [Ruby on Rails](#ruby-on-rails)
+* [Visual Basic](#visual-basic)
 
 ###Android