diff --git a/Concurrency programming/PP - 9. Skip list/pom.xml b/Concurrency programming/PP - 9. Skip list/pom.xml
index 9616fbc..a8989fe 100644
--- a/Concurrency programming/PP - 9. Skip list/pom.xml	
+++ b/Concurrency programming/PP - 9. Skip list/pom.xml	
@@ -15,7 +15,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.12</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
         <dependency>