diff --git a/core-groovy-2/README.md b/core-groovy-2/README.md
index f60bdb3cbe..cc9e69a4b6 100644
--- a/core-groovy-2/README.md
+++ b/core-groovy-2/README.md
@@ -3,5 +3,5 @@
 ## Relevant articles:
 
 - [String Matching in Groovy](http://www.baeldung.com/)
-- [Groovy def Keyword]
+- [Groovy def Keyword](https://www.baeldung.com/groovy-def-keyword)