diff --git a/4_Authentication/complete/pom.xml b/4_Authentication/complete/pom.xml
index 4343b8b..c97c65c 100644
--- a/4_Authentication/complete/pom.xml
+++ b/4_Authentication/complete/pom.xml
@@ -55,7 +55,7 @@
 		<dependency>
 			<groupId>ch.qos.logback</groupId>
 			<artifactId>logback-classic</artifactId>
-			<version>1.2.3</version>
+			<version>1.2.13</version>
 		</dependency>
 		<dependency>
 			<groupId>com.yubico</groupId>