diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/AbstractPingIndicator.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/AbstractPingIndicator.java
index 553d972d..a67a7546 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/AbstractPingIndicator.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/AbstractPingIndicator.java
@@ -77,7 +77,9 @@ public abstract class AbstractPingIndicator extends AbstractClientIndicator {
             // Update last ping time on persistent storage
             final long millisecondsNow = DateTimeUtils.currentTimeMillis();
             if (millisecondsNow - this.lastUpdate > INTERVAL_FOR_PERSISTENT_UPDATE) {
-                this.distributedPingCache.updatePing(this.pingRecord, millisecondsNow);
+                synchronized (this) {
+                    this.distributedPingCache.updatePing(this.pingRecord, millisecondsNow);
+                }
             }
         }
     }
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/DistributedPingCache.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/DistributedPingCache.java
index 5d170162..979df7fa 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/DistributedPingCache.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/indicator/DistributedPingCache.java
@@ -24,6 +24,7 @@ import org.springframework.beans.factory.DisposableBean;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Isolation;
 import org.springframework.transaction.annotation.Transactional;
 
 import ch.ethz.seb.sebserver.gbl.model.session.ClientEvent.EventType;
@@ -180,7 +181,7 @@ public class DistributedPingCache implements DisposableBean {
         }
     }
 
-    @Transactional(readOnly = true)
+    @Transactional(readOnly = true, isolation = Isolation.READ_UNCOMMITTED)
     public void updateCache() {
 
         if (this.pingCache.isEmpty()) {