diff --git a/apps/server/src/core/comment/comment.service.apply-suggestion.spec.ts b/apps/server/src/core/comment/comment.service.apply-suggestion.spec.ts
index bcfc2f2c..100dae67 100644
--- a/apps/server/src/core/comment/comment.service.apply-suggestion.spec.ts
+++ b/apps/server/src/core/comment/comment.service.apply-suggestion.spec.ts
@@ -197,17 +197,25 @@ describe('CommentService — applySuggestion', () => {
     expect(resolvePatch.resolvedAt).toBeInstanceOf(Date);
     expect(resolvePatch.resolvedById).toBe('user-1');
 
-    // NOT deleted; broadcast an update, not a deletion.
+    // NOT deleted.
     expect(commentRepo.deleteComment).not.toHaveBeenCalled();
     expect(collaborationGateway.handleYjsEvent).not.toHaveBeenCalledWith(
       'deleteCommentMark',
       expect.anything(),
       expect.anything(),
     );
+    // #496 dedup: resolveComment broadcasts `commentResolved` with the enriched
+    // row; finalize must NOT ALSO emit a redundant `commentUpdated`. So the
+    // thread receives exactly ONE resolve broadcast and no update broadcast.
     expect(wsService.emitCommentEvent).toHaveBeenCalledWith(
       'space-1',
       'page-1',
-      expect.objectContaining({ operation: 'commentUpdated', comment: UPDATED }),
+      expect.objectContaining({ operation: 'commentResolved', comment: UPDATED }),
+    );
+    expect(wsService.emitCommentEvent).not.toHaveBeenCalledWith(
+      'space-1',
+      'page-1',
+      expect.objectContaining({ operation: 'commentUpdated' }),
     );
 
     expect(auditService.log).toHaveBeenCalledWith(
@@ -219,6 +227,36 @@ describe('CommentService — applySuggestion', () => {
     expect(result.outcome).toBe('resolved');
   });
 
+  it('re-entry: already applied+resolved WITH replies → emits commentUpdated (dedup does not over-suppress)', async () => {
+    // suggestionAppliedAt set → idempotent finalize; resolvedAt set → resolveComment
+    // is skipped, so there is NO commentResolved broadcast. The applied-stamp state
+    // must still reach clients via a single commentUpdated.
+    const { service, wsService } = makeService(
+      { applied: false, currentText: 'new text' },
+      true,
+    );
+
+    await service.applySuggestion(
+      suggestionComment({
+        suggestionAppliedAt: new Date(),
+        resolvedAt: new Date(),
+      }),
+      user(),
+    );
+
+    expect(wsService.emitCommentEvent).toHaveBeenCalledWith(
+      'space-1',
+      'page-1',
+      expect.objectContaining({ operation: 'commentUpdated', comment: UPDATED }),
+    );
+    // Nothing resolved this time (already resolved) → no resolve broadcast.
+    expect(wsService.emitCommentEvent).not.toHaveBeenCalledWith(
+      'space-1',
+      'page-1',
+      expect.objectContaining({ operation: 'commentResolved' }),
+    );
+  });
+
   // --- error / rejection branches -----------------------------------------
 
   it('applied=false and currentText differs → ConflictException with currentText in payload', async () => {
diff --git a/apps/server/src/core/comment/comment.service.ts b/apps/server/src/core/comment/comment.service.ts
index c053ccf8..88122e96 100644
--- a/apps/server/src/core/comment/comment.service.ts
+++ b/apps/server/src/core/comment/comment.service.ts
@@ -577,8 +577,10 @@ export class CommentService {
 
       // Auto-resolve the thread. resolveComment handles the resolve mark, its ws
       // broadcast and the resolve notification. Stay defensive on re-entry.
+      let didResolveBroadcast = false;
       if (!comment.resolvedAt) {
         await this.resolveComment(comment, true, user, provenance);
+        didResolveBroadcast = true;
       }
 
       const updatedComment = await this.commentRepo.findById(comment.id, {
@@ -586,11 +588,20 @@ export class CommentService {
         includeResolvedBy: true,
       });
 
-      this.wsService.emitCommentEvent(comment.spaceId, comment.pageId, {
-        operation: 'commentUpdated',
-        pageId: comment.pageId,
-        comment: updatedComment,
-      });
+      // #496 dedup: resolveComment already broadcast `commentResolved` carrying
+      // the fully-enriched row (the applied stamps were persisted above, before
+      // that call, so its re-read reflects them). Emitting `commentUpdated` here
+      // too made the client receive TWO events for one apply. Broadcast the
+      // update ONLY when we did NOT resolve — i.e. the rare re-entry on an
+      // already-resolved thread, where the applied-stamp change still needs a
+      // broadcast and resolveComment did not run.
+      if (!didResolveBroadcast) {
+        this.wsService.emitCommentEvent(comment.spaceId, comment.pageId, {
+          operation: 'commentUpdated',
+          pageId: comment.pageId,
+          comment: updatedComment,
+        });
+      }
 
       this.auditService.log({
         event: AuditEvent.COMMENT_SUGGESTION_APPLIED,