diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96ed4c849..ea5be0c8a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ FROST-Server version 2.5 and higher requires Java 21. This is because some libra
 * Apply fine-grained authorisation to MQTT-Create.
 * Fixed the resolving of references in the URL of json batch requests.
 * Fixed differences in HTTP response code between GET and HEAD requests.
+* Fixed json batch requests without atomicity group all running in the same group.
 
 
 ## Release version 2.4.0
diff --git a/Plugins/BatchProcessing/src/main/java/de/fraunhofer/iosb/ilt/frostserver/plugin/batchprocessing/json/JsonBatchProcessor.java b/Plugins/BatchProcessing/src/main/java/de/fraunhofer/iosb/ilt/frostserver/plugin/batchprocessing/json/JsonBatchProcessor.java
index 3fc39d09e..4d71a3153 100644
--- a/Plugins/BatchProcessing/src/main/java/de/fraunhofer/iosb/ilt/frostserver/plugin/batchprocessing/json/JsonBatchProcessor.java
+++ b/Plugins/BatchProcessing/src/main/java/de/fraunhofer/iosb/ilt/frostserver/plugin/batchprocessing/json/JsonBatchProcessor.java
@@ -149,7 +149,7 @@ public void processNextRequest() {
             if (parser.nextToken() == JsonToken.START_OBJECT) {
                 JsonBatchRequestItem item = parser.readValueAs(JsonBatchRequestItem.class);
                 final String itemGroup = item.getAtomicityGroup();
-                if (!StringUtils.equals(currentGroup, itemGroup)) {
+                if (itemGroup == null || !StringUtils.equals(currentGroup, itemGroup)) {
                     service.commitTransaction();
                     service.startTransaction(request.getUserPrincipal());
                     currentGroup = itemGroup;