diff --git a/lib/shared/messages/reaction-message-spec.js b/lib/shared/messages/reaction-message-spec.js
--- a/lib/shared/messages/reaction-message-spec.js
+++ b/lib/shared/messages/reaction-message-spec.js
@@ -7,6 +7,7 @@
   type MessageSpec,
   type MessageTitleParam,
   pushTypes,
+  type ShowInMessagePreviewParams,
 } from './message-spec.js';
 import { assertSingleMessageInfo, joinResult } from './utils.js';
 import type { PlatformDetails } from '../../types/device-types.js';
@@ -225,4 +226,17 @@
   canBeRenderedIndependently: false,
 
   validator: rawReactionMessageInfoValidator,
+
+  showInMessagePreview: async (
+    messageInfo: ReactionMessageInfo,
+    params: ShowInMessagePreviewParams,
+  ) => {
+    const originalMessage = await params.fetchMessage(
+      messageInfo.targetMessageID,
+    );
+    if (!originalMessage) {
+      return false;
+    }
+    return originalMessage.creatorID === params.viewerID;
+  },
 });