diff --git a/tests/k6/tests/serviceowner/all-tests.js b/tests/k6/tests/serviceowner/all-tests.js
index 33ded10ca..354216354 100644
--- a/tests/k6/tests/serviceowner/all-tests.js
+++ b/tests/k6/tests/serviceowner/all-tests.js
@@ -7,6 +7,7 @@ import { default as dialogCreateExternalResource } from './dialogCreateExternalR
 import { default as dialogCreateInvalidActionCount } from './dialogCreateInvalidActionCount.js';
 import { default as dialogCreatePatchDelete } from './dialogCreatePatchDelete.js';
 import { default as dialogSearch } from './dialogSearch.js';
+import { default as dialogUpdateActivity } from './dialogUpdateActivity.js';
 
 export default function() {
   authentication();
@@ -17,4 +18,5 @@ export default function() {
   dialogCreateInvalidActionCount();
   dialogCreatePatchDelete();
   dialogSearch();
+  dialogUpdateActivity();
 }
diff --git a/tests/k6/tests/serviceowner/dialogCreateActivity.js b/tests/k6/tests/serviceowner/dialogCreateActivity.js
index b7d4ec41f..950e3d95e 100644
--- a/tests/k6/tests/serviceowner/dialogCreateActivity.js
+++ b/tests/k6/tests/serviceowner/dialogCreateActivity.js
@@ -4,7 +4,6 @@ import {
     expectStatusFor,
     postSO,
     purgeSO,
-    uuidv4,
     uuidv7,
     setActivities,
     addActivity
@@ -18,9 +17,9 @@ export default function () {
         let dialog = dialogToInsert();
         let activities = [{
             'id': uuidv7(),
-            'type': 'dialogOpened',
-            'performedBy': {
-                'actorType': 'ServiceOwner'
+            'type': 'dialogopened',
+            'performedby': {
+                'actortype': 'serviceowner'
             }
         }]
 
diff --git a/tests/k6/tests/serviceowner/dialogUpdateActivity.js b/tests/k6/tests/serviceowner/dialogUpdateActivity.js
new file mode 100644
index 000000000..98dc608df
--- /dev/null
+++ b/tests/k6/tests/serviceowner/dialogUpdateActivity.js
@@ -0,0 +1,115 @@
+import {
+    describe,
+    expect,
+    expectStatusFor,
+    postSO,
+    putSO,
+    purgeSO,
+    uuidv7,
+    setActivities,
+    addActivity,
+    setTitle
+} from '../../common/testimports.js'
+import {default as dialogToInsert} from './testdata/01-create-dialog.js';
+
+export default function () {
+    let dialogIds = [];
+    let dialogs = [];
+    let currentDialog = 0;
+    let dialogAmount = 4;
+    describe('Arrange: Create some dialogs to test against', () => {
+
+
+        for (let i = 0; i < dialogAmount; i++) {
+            let d = dialogToInsert();
+            setTitle(d, "e2e-test-dialog #" + (i + 1), "nn_NO");
+            setActivities(d);
+            let r = postSO('dialogs', d);
+            expectStatusFor(r).to.equal(201);
+            dialogs.push(d)
+            dialogIds.push(r.json());
+        }
+
+    })
+
+    describe('Update dialog with invalid transmissionOpened activity', () => {
+        let dialog = dialogs[currentDialog];
+        dialog.id = dialogIds[currentDialog];
+        currentDialog++;
+        let activities = [{
+            'id': uuidv7(),
+            'type': 'transmissionOpened',
+            'performedBy': {
+                'actorType': 'ServiceOwner'
+            }
+        }]
+        setActivities(dialog, activities);
+
+        let response = putSO('dialogs/' + dialog.id, dialog);
+        expectStatusFor(response).to.equal(400);
+    })
+
+
+    describe('Update dialog with invalid dialogOpened activity', () => {
+        let dialog = dialogs[currentDialog];
+        dialog.id = dialogIds[currentDialog];
+        currentDialog++;
+        let transmissionId = uuidv7();
+        dialog.transmissionId = transmissionId;
+        let activities = [{
+            'id': uuidv7(),
+            'type': 'dialogOpened',
+            'transmissionId': transmissionId,
+            'performedBy': {
+                'actorType': 'ServiceOwner'
+            }
+        }]
+        setActivities(dialog, activities);
+
+        let response = putSO('dialogs/' + dialog.id, dialog);
+        expectStatusFor(response).to.equal(400);
+    })
+
+    describe('Update dialog with transmissionOpened activity', () => {
+        let dialog = dialogs[currentDialog];
+        dialog.id = dialogIds[currentDialog];
+        currentDialog++;
+        let transmissionId = uuidv7();
+        dialog.transmissions[0].id = transmissionId;
+        let activities = [{
+            'id': uuidv7(),
+            'type': 'transmissionOpened',
+            'transmissionId': transmissionId,
+            'performedBy': {
+                'actorType': 'ServiceOwner'
+            }
+        }]
+        setActivities(dialog, activities);
+
+        let response = putSO('dialogs/' + dialog.id, dialog);
+        expectStatusFor(response).to.equal(204);
+    })
+
+    describe('Update dialog with dialogOpened activity', () => {
+        let dialog = dialogs[currentDialog];
+        dialog.id = dialogIds[currentDialog];
+        currentDialog++;
+        let activities = [{
+            'id': uuidv7(),
+            'type': 'dialogOpened',
+            'performedBy': {
+                'actorType': 'ServiceOwner'
+            }
+        }]
+        setActivities(dialog, activities);
+
+        let response = putSO('dialogs/' + dialog.id, dialog);
+        expectStatusFor(response).to.equal(204);
+    })
+    describe('Cleanup', () => {
+        dialogIds.forEach((d) => {
+            let r = purgeSO('dialogs/' + d);
+            expectStatusFor(r).to.equal(204);
+        })
+    })
+}