diff --git a/free-programming-books.md b/free-programming-books.md
index 948213883..f0cdde298 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -32,7 +32,7 @@
 * [C](#c)
 * [C++](#c-1)
 * [Clojure](#clojure)
-* [COBOL] (#COBOL)
+* [COBOL] (#cobol)
 * [CoffeeScript](#coffeescript)
 * [ColdFusion](#coldfusion)
 * [Coq](#coq)