diff --git a/src/main/java/de/thm/arsnova/services/SessionService.java b/src/main/java/de/thm/arsnova/services/SessionService.java
index a9aa671c9c0b3d70a35df770925d389499413074..8d7b93de902d8b30c6ba329bd9f8d851d49427e7 100644
--- a/src/main/java/de/thm/arsnova/services/SessionService.java
+++ b/src/main/java/de/thm/arsnova/services/SessionService.java
@@ -100,7 +100,6 @@ public class SessionService implements ISessionService, ApplicationEventPublishe
 	}
 
 	private static final long SESSION_INACTIVITY_CHECK_INTERVAL_MS = 30 * 60 * 1000L;
-	private static final long SESSION_INACTIVITY_THRESHOLD_MS = 90 * 24 * 60 * 60 * 1000L;
 
 	@Autowired
 	private IDatabaseDao databaseDao;
@@ -120,6 +119,9 @@ public class SessionService implements ISessionService, ApplicationEventPublishe
 	@Autowired
 	private ImageUtils imageUtils;
 
+	@Value("${session.guest-session.cleanup-days:0}")
+	private int guestSessionInactivityThresholdDays;
+
 	@Value("${pp.logofilesize_b}")
 	private int uploadFileSizeByte;
 
@@ -129,10 +131,12 @@ public class SessionService implements ISessionService, ApplicationEventPublishe
 
 	@Scheduled(fixedDelay = SESSION_INACTIVITY_CHECK_INTERVAL_MS)
 	public void deleteInactiveSessions() {
-		LOGGER.info("Delete inactive sessions.");
-		long unixTime = System.currentTimeMillis();
-		long lastActivityBefore = unixTime - SESSION_INACTIVITY_THRESHOLD_MS;
-		databaseDao.deleteInactiveGuestSessions(lastActivityBefore);
+		if (guestSessionInactivityThresholdDays > 0) {
+			LOGGER.info("Delete inactive sessions.");
+			long unixTime = System.currentTimeMillis();
+			long lastActivityBefore = unixTime - guestSessionInactivityThresholdDays * 24 * 60 * 60 * 1000L;
+			databaseDao.deleteInactiveGuestSessions(lastActivityBefore);
+		}
 	}
 
 	public void setDatabaseDao(final IDatabaseDao newDatabaseDao) {
diff --git a/src/main/resources/arsnova.properties.example b/src/main/resources/arsnova.properties.example
index 294847eaf28d4b9f2e1482058f845219fcf6fcea..34fa9b0a1d80f6a0a91fa1bbd5e3d77c239494e8 100644
--- a/src/main/resources/arsnova.properties.example
+++ b/src/main/resources/arsnova.properties.example
@@ -243,6 +243,9 @@ question.parse-answer-option-formatting=false
 # https://github.com/thm-projects/arsnova-mobile/tree/master/demo-sessions
 session.demo-id=
 
+# Delete guest sessions automatically after X days of owner inactivity.
+#session.guest-session.cleanup-days=180
+
 # Label underneath ARSnova logo
 ui.slogan=Audience Response System
 
diff --git a/src/test/resources/arsnova.properties.example b/src/test/resources/arsnova.properties.example
index 294847eaf28d4b9f2e1482058f845219fcf6fcea..34fa9b0a1d80f6a0a91fa1bbd5e3d77c239494e8 100644
--- a/src/test/resources/arsnova.properties.example
+++ b/src/test/resources/arsnova.properties.example
@@ -243,6 +243,9 @@ question.parse-answer-option-formatting=false
 # https://github.com/thm-projects/arsnova-mobile/tree/master/demo-sessions
 session.demo-id=
 
+# Delete guest sessions automatically after X days of owner inactivity.
+#session.guest-session.cleanup-days=180
+
 # Label underneath ARSnova logo
 ui.slogan=Audience Response System