diff --git a/src/main/java/caosdb/server/database/misc/TransactionBenchmark.java b/src/main/java/caosdb/server/database/misc/TransactionBenchmark.java
index d68c82f5581d91d73797d014431250d0953f6e41..2d263df490a5d54abd35bef1005b2980c66f1bae 100644
--- a/src/main/java/caosdb/server/database/misc/TransactionBenchmark.java
+++ b/src/main/java/caosdb/server/database/misc/TransactionBenchmark.java
@@ -130,7 +130,7 @@ class Measurement implements Serializable {
 
 class RootBenchmark extends TransactionBenchmark implements ServerStat {
 
-  private static final long serialVersionUID = 8070554107783826602L;
+  private static final long serialVersionUID = 8070554107783826603L;
   private transient boolean synced = false;
   /**
    * Fetch old data (from before last shutdown) and fill it into this instance.
@@ -142,7 +142,6 @@ class RootBenchmark extends TransactionBenchmark implements ServerStat {
     synchronized (this.measurements) {
       final Runnable updater =
           new Runnable() {
-
             @Override
             public void run() {
               try {
@@ -209,7 +208,7 @@ class RootBenchmark extends TransactionBenchmark implements ServerStat {
 
 class SubBenchmark extends TransactionBenchmark {
 
-  private static final long serialVersionUID = 323147917189195973L;
+  private static final long serialVersionUID = 323147917189195974L;
   private final String name;
 
   public SubBenchmark(String name) {
@@ -271,7 +270,7 @@ class JdomConverter {
  */
 public abstract class TransactionBenchmark implements Serializable {
 
-  private static final long serialVersionUID = -8916163825450491067L;
+  private static final long serialVersionUID = -8916163825450491068L;
   private static final TransactionBenchmark rootService = new RootBenchmark().init();
   public final transient Logger logger = LogManager.getLogger(getClass());
   protected static final transient boolean isActive =
@@ -426,7 +425,7 @@ public abstract class TransactionBenchmark implements Serializable {
     return this.createBenchmark(class1.getSimpleName());
   }
 
-  /** Return a String denoting where this TransactionBenchmark was created from. */
+  /** Return a String (or null) denoting where this TransactionBenchmark was created from. */
   public String called_from() {
     final int stackSize = stackTraceElements.length;
     if (stackSize <= 5) {