diff --git a/Section 1/Chapter04/tracked-hashtag-service/pom.xml b/Section 1/Chapter04/tracked-hashtag-service/pom.xml
index 6b37a53..c33beef 100644
--- a/Section 1/Chapter04/tracked-hashtag-service/pom.xml	
+++ b/Section 1/Chapter04/tracked-hashtag-service/pom.xml	
@@ -23,7 +23,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <java.version>1.8</java.version>
-    <kotlin.version>1.2.0</kotlin.version>
+    <kotlin.version>1.6.0</kotlin.version>
   </properties>
 
   <dependencies>