diff --git a/authentication/source/java/ch/systemsx/cisd/authentication/DefaultSessionManager.java b/authentication/source/java/ch/systemsx/cisd/authentication/DefaultSessionManager.java
index 1f9838d0d4619124c7b985888fbb8d13f78a27f4..ed554f458c4578fb4b185aa0ea97c58bdc38a9dc 100644
--- a/authentication/source/java/ch/systemsx/cisd/authentication/DefaultSessionManager.java
+++ b/authentication/source/java/ch/systemsx/cisd/authentication/DefaultSessionManager.java
@@ -139,8 +139,8 @@ public class DefaultSessionManager<T extends BasicSession> implements ISessionMa
 
         operationLog.info(String.format("Authentication service: '%s'", authenticationService
                 .getClass().getName()));
-        operationLog.info(String.format("Session expiration period (ms): %d",
-                sessionExpirationPeriodMillis));
+        operationLog.info(String.format("Session expiration period: %s", DurationFormatUtils
+                .formatDurationHMS(sessionExpirationPeriodMillis)));
         authenticationService.check();
     }