diff --git a/static/app/components/feedback/feedbackItem/feedbackActivitySection.spec.tsx b/static/app/components/feedback/feedbackItem/feedbackActivitySection.spec.tsx
index d4d65a967e58..b86a8aee4e45 100644
--- a/static/app/components/feedback/feedbackItem/feedbackActivitySection.spec.tsx
+++ b/static/app/components/feedback/feedbackItem/feedbackActivitySection.spec.tsx
@@ -42,6 +42,7 @@ describe('FeedbackActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'Existing feedback note'},
           dateCreated: '2020-01-01T00:00:00',
           user,
@@ -89,6 +90,7 @@ describe('FeedbackActivitySection', () => {
       method: 'POST',
       body: {
         id: 'note-2',
+        commentId: 'note-2',
         user,
         type: 'note',
         data: {text: comment},
@@ -127,6 +129,7 @@ describe('FeedbackActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'Existing feedback note'},
           dateCreated: '2020-01-01T00:00:00',
           user,
diff --git a/static/app/types/group.tsx b/static/app/types/group.tsx
index 40101c2b3522..00162b99aeca 100644
--- a/static/app/types/group.tsx
+++ b/static/app/types/group.tsx
@@ -708,11 +708,11 @@ export interface GroupActivityIntegrationData {
 }
 
 export interface GroupActivityNote extends GroupActivityBase {
+  commentId: string;
   data: {
     text: string;
   };
   type: GroupActivityType.NOTE;
-  commentId?: string;
 }
 
 interface GroupActivitySetResolved extends GroupActivityBase {
diff --git a/static/app/views/issueDetails/activitySection/activityLineItem.stories.tsx b/static/app/views/issueDetails/activitySection/activityLineItem.stories.tsx
index 8d2c179c62a8..8cf90deb92c8 100644
--- a/static/app/views/issueDetails/activitySection/activityLineItem.stories.tsx
+++ b/static/app/views/issueDetails/activitySection/activityLineItem.stories.tsx
@@ -431,6 +431,7 @@ function activity(
   actor: GroupActivity['user'] = user
 ): GroupActivity {
   return {
+    ...(type === GroupActivityType.NOTE ? {commentId: type} : {}),
     data,
     dateCreated: '2025-01-01T00:00:00Z',
     id: type,
diff --git a/static/app/views/issueDetails/activitySection/index.spec.tsx b/static/app/views/issueDetails/activitySection/index.spec.tsx
index f59298aa3958..5c1ec6fd29ec 100644
--- a/static/app/views/issueDetails/activitySection/index.spec.tsx
+++ b/static/app/views/issueDetails/activitySection/index.spec.tsx
@@ -54,6 +54,7 @@ describe('ActivitySection', () => {
       {
         type: GroupActivityType.NOTE,
         id: 'note-1',
+        commentId: 'note-1',
         data: {text: 'Test Note'},
         dateCreated: '2020-01-01T00:00:00',
         user,
@@ -82,6 +83,7 @@ describe('ActivitySection', () => {
       method: 'POST',
       body: {
         id: 'note-2',
+        commentId: 'note-2',
         user: UserFixture({id: '2'}),
         type: 'note',
         data: {text: comment},
@@ -122,6 +124,7 @@ describe('ActivitySection', () => {
       method: 'POST',
       body: {
         id: 'note-3',
+        commentId: 'note-3',
         user: UserFixture({id: '2'}),
         type: 'note',
         data: {text: comment},
@@ -152,6 +155,7 @@ describe('ActivitySection', () => {
       method: 'POST',
       body: {
         id: 'note-4',
+        commentId: 'note-4',
         user: UserFixture({id: '2'}),
         type: 'note',
         data: {text: '@Jane Doe'},
@@ -181,12 +185,14 @@ describe('ActivitySection', () => {
     );
   });
 
-  it.each([
-    {id: '123', commentId: undefined},
-    {id: '987', commentId: '123'},
-  ])('deletes only the comment with identity %j', async identity => {
+  it('deletes only the referenced comment', async () => {
     jest.spyOn(indicators, 'addSuccessMessage');
-    const note = ActivityFeedFixture({...identity, user, data: {text: 'Test Note'}});
+    const note = ActivityFeedFixture({
+      id: '987',
+      commentId: '123',
+      user,
+      data: {text: 'Test Note'},
+    });
     const resolution = ActivityFeedFixture({
       id: '123',
       type: GroupActivityType.SET_RESOLVED,
@@ -234,6 +240,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'Undeletable Note'},
           dateCreated: '2020-01-01T00:00:00',
           user,
@@ -274,6 +281,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: '**Bold Note** and [docs](https://docs.sentry.io/)'},
           dateCreated: tenMinutesAgo(),
           user,
@@ -305,6 +313,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'User note'},
           dateCreated: '2020-01-01T00:00:00',
           user,
@@ -875,6 +884,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'This note came from my sentry app'},
           dateCreated: '2020-01-01T00:00:00',
           sentry_app: sentryApp,
@@ -932,6 +942,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-1',
+          commentId: 'note-1',
           data: {text: 'Test Note'},
           dateCreated: '2020-01-01T00:00:00',
           user: UserFixture({id: '2'}),
@@ -959,6 +970,7 @@ describe('ActivitySection', () => {
     const activities: GroupActivity[] = Array.from({length: 7}, (_, index) => ({
       type: GroupActivityType.NOTE,
       id: `note-${index + 1}`,
+      commentId: `note-${index + 1}`,
       data: {text: `Test Note ${index + 1}`},
       dateCreated: '2020-01-01T00:00:00',
       user: UserFixture({id: '2'}),
@@ -989,6 +1001,7 @@ describe('ActivitySection', () => {
     const activities: GroupActivity[] = Array.from({length: 3}, (_, index) => ({
       type: GroupActivityType.NOTE,
       id: `note-${index + 1}`,
+      commentId: `note-${index + 1}`,
       data: {text: `Test Note ${index + 1}`},
       dateCreated: '2020-01-01T00:00:00',
       user: UserFixture({id: '2'}),
@@ -1026,6 +1039,7 @@ describe('ActivitySection', () => {
     const activities: GroupActivity[] = Array.from({length: 7}, (_, index) => ({
       type: GroupActivityType.NOTE,
       id: `note-${index + 1}`,
+      commentId: `note-${index + 1}`,
       data: {text: `Test Note ${index + 1}`},
       dateCreated: tenMinutesAgo(),
       user: UserFixture({id: '2'}),
@@ -1114,6 +1128,7 @@ describe('ActivitySection', () => {
     const activities: GroupActivity[] = Array.from({length: 3}, (_, index) => ({
       type: GroupActivityType.NOTE,
       id: `note-${index + 1}`,
+      commentId: `note-${index + 1}`,
       data: {text: `Test Note ${index + 1}`},
       dateCreated: '2020-01-01T00:00:00',
       user: UserFixture({id: '2'}),
@@ -1788,6 +1803,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'note-between-pull-request-activities',
+          commentId: 'note-between-pull-request-activities',
           dateCreated: '2020-01-01T00:01:00',
           data: {text: 'An activity between the pull request activities'},
           user,
@@ -2065,6 +2081,7 @@ describe('ActivitySection', () => {
         {
           type: GroupActivityType.NOTE,
           id: 'activity-during-rca',
+          commentId: 'activity-during-rca',
           dateCreated: '2020-01-01T00:02:00Z',
           data: {text: 'Checked during analysis'},
           user,
diff --git a/static/app/views/issueDetails/activitySection/index.tsx b/static/app/views/issueDetails/activitySection/index.tsx
index dcbfba17f524..a59b4ecc5508 100644
--- a/static/app/views/issueDetails/activitySection/index.tsx
+++ b/static/app/views/issueDetails/activitySection/index.tsx
@@ -44,7 +44,7 @@ interface ActivityFeedRowProps {
 
 function getActivityKey(activity: GroupActivity): string {
   return isActivityNote(activity)
-    ? `comment:${activity.commentId ?? activity.id}`
+    ? `comment:${activity.commentId}`
     : `activity:${activity.id}`;
 }
 
@@ -151,28 +151,27 @@ export function ActivitySection({
   }
 
   async function handleDelete(item: GroupActivityNote) {
-    const commentId = item.commentId ?? item.id;
+    const commentId = item.commentId;
     await deleteComment(commentId);
     trackAnalytics('issue_details.comment_deleted', {organization});
     addSuccessMessage(t('Comment removed'));
     onActivityChange?.(
       activities.filter(
-        activity =>
-          !isActivityNote(activity) || (activity.commentId ?? activity.id) !== commentId
+        activity => !isActivityNote(activity) || activity.commentId !== commentId
       )
     );
   }
 
   async function handleUpdate(item: GroupActivityNote, data: NoteType) {
     try {
-      const commentId = item.commentId ?? item.id;
+      const commentId = item.commentId;
       const result = await updateComment(commentId, data);
       trackAnalytics('issue_details.comment_updated', {organization});
       addSuccessMessage(t('Comment updated'));
       onActivityChange?.(
         activities.map(activity =>
-          isActivityNote(activity) && (activity.commentId ?? activity.id) === commentId
-            ? {...activity, commentId, data: {...activity.data, ...result.data}}
+          isActivityNote(activity) && activity.commentId === commentId
+            ? {...activity, data: {...activity.data, ...result.data}}
             : activity
         )
       );
diff --git a/static/app/views/issueDetails/activitySection/useMutateActivity.tsx b/static/app/views/issueDetails/activitySection/useMutateActivity.tsx
index 92bde5295897..a7e09c4506e3 100644
--- a/static/app/views/issueDetails/activitySection/useMutateActivity.tsx
+++ b/static/app/views/issueDetails/activitySection/useMutateActivity.tsx
@@ -86,11 +86,9 @@ export function useMutateActivity({organization, group}: Props) {
           case 'PUT':
             return updateGroup(
               prev.json.activity.map(item =>
-                item.type === GroupActivityType.NOTE &&
-                (item.commentId ?? item.id) === mutation.noteId
+                item.type === GroupActivityType.NOTE && item.commentId === mutation.noteId
                   ? {
                       ...item,
-                      commentId: mutation.noteId,
                       data: {...item.data, ...result.data},
                     }
                   : item
@@ -102,7 +100,7 @@ export function useMutateActivity({organization, group}: Props) {
               prev.json.activity.filter(
                 item =>
                   item.type !== GroupActivityType.NOTE ||
-                  (item.commentId ?? item.id) !== mutation.noteId
+                  item.commentId !== mutation.noteId
               ),
               prev.json.numComments - 1
             );
diff --git a/static/app/views/issueDetails/sidebar/sidebar.spec.tsx b/static/app/views/issueDetails/sidebar/sidebar.spec.tsx
index a83b3cccde02..f108969d4c65 100644
--- a/static/app/views/issueDetails/sidebar/sidebar.spec.tsx
+++ b/static/app/views/issueDetails/sidebar/sidebar.spec.tsx
@@ -32,6 +32,7 @@ describe('IssueDetailsSidebar', () => {
       {
         type: GroupActivityType.NOTE,
         id: 'note-1',
+        commentId: 'note-1',
         data: {text: activityContent},
         dateCreated: '2020-01-01T00:00:00',
         user,
diff --git a/static/app/views/issueList/progressActivityTooltip.spec.tsx b/static/app/views/issueList/progressActivityTooltip.spec.tsx
index aaa6da11a890..c36992423e65 100644
--- a/static/app/views/issueList/progressActivityTooltip.spec.tsx
+++ b/static/app/views/issueList/progressActivityTooltip.spec.tsx
@@ -96,6 +96,7 @@ describe('ProgressActivityTooltip', () => {
   it('shows comment text', async () => {
     const noteActivity: GroupActivity = {
       id: 'activity-4',
+      commentId: 'activity-4',
       type: GroupActivityType.NOTE,
       data: {text: 'This is the useful part of the comment.'},
       dateCreated: '2024-01-04T00:00:00.000Z',
diff --git a/tests/js/fixtures/activityFeed.ts b/tests/js/fixtures/activityFeed.ts
index 805a6ee8462a..a65ade05f502 100644
--- a/tests/js/fixtures/activityFeed.ts
+++ b/tests/js/fixtures/activityFeed.ts
@@ -8,6 +8,7 @@ import {GroupActivityType, IssueCategory, IssueType} from 'sentry/types/group';
 
 export function ActivityFeedFixture(params: Partial<Activity> = {}): Activity {
   return {
+    commentId: params.id ?? '42',
     data: {text: 'Very interesting comment'},
     dateCreated: '2019-04-29T21:43:32.280Z',
     user: UserFixture({