diff --git a/core-kotlin-modules/core-kotlin-lang-2/README.md b/core-kotlin-modules/core-kotlin-lang-2/README.md
index 9a0d626553..52833804ed 100644
--- a/core-kotlin-modules/core-kotlin-lang-2/README.md
+++ b/core-kotlin-modules/core-kotlin-lang-2/README.md
@@ -13,4 +13,5 @@ This module contains articles about core features in the Kotlin language.
 - [Kotlin Scope Functions](https://www.baeldung.com/kotlin-scope-functions)
 - [Checking Whether a lateinit var Is Initialized in Kotlin](https://www.baeldung.com/kotlin/checking-lateinit)
 - [If-Else Expression in Kotlin](https://www.baeldung.com/kotlin/if-else-expression)
+- [Not-Null Assertion (!!) Operator in Kotlin](https://www.baeldung.com/kotlin/not-null-assertion)
 - [[<-- Prev]](/core-kotlin-modules/core-kotlin-lang)