diff --git a/lib/hooks/message-hooks.js b/lib/hooks/message-hooks.js
--- a/lib/hooks/message-hooks.js
+++ b/lib/hooks/message-hooks.js
@@ -71,10 +71,13 @@
             shouldFetchOlderMessages: false,
           };
         }
-        const shouldShow = await showInMessagePreview(
+        let shouldShow = showInMessagePreview(
           messageInfo,
           showInMessagePreviewParams,
         );
+        if (shouldShow instanceof Promise) {
+          shouldShow = await shouldShow;
+        }
         if (shouldShow) {
           return {
             messageInfoForPreview: messageInfo,
diff --git a/lib/shared/messages/add-members-message-spec.js b/lib/shared/messages/add-members-message-spec.js
--- a/lib/shared/messages/add-members-message-spec.js
+++ b/lib/shared/messages/add-members-message-spec.js
@@ -229,7 +229,7 @@
     return { shouldMerge: true, item: mergedItem };
   },
 
-  showInMessagePreview: async (
+  showInMessagePreview: (
     messageInfo: AddMembersMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => threadTypeIsThick(params.threadInfo.type),
diff --git a/lib/shared/messages/join-thread-message-spec.js b/lib/shared/messages/join-thread-message-spec.js
--- a/lib/shared/messages/join-thread-message-spec.js
+++ b/lib/shared/messages/join-thread-message-spec.js
@@ -175,7 +175,7 @@
     return { shouldMerge: true, item: mergedItem };
   },
 
-  showInMessagePreview: async (
+  showInMessagePreview: (
     messageInfo: JoinThreadMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => threadTypeIsThick(params.threadInfo.type),
diff --git a/lib/shared/messages/leave-thread-message-spec.js b/lib/shared/messages/leave-thread-message-spec.js
--- a/lib/shared/messages/leave-thread-message-spec.js
+++ b/lib/shared/messages/leave-thread-message-spec.js
@@ -175,7 +175,7 @@
     return { shouldMerge: true, item: mergedItem };
   },
 
-  showInMessagePreview: async (
+  showInMessagePreview: (
     messageInfo: LeaveThreadMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => threadTypeIsThick(params.threadInfo.type),
diff --git a/lib/shared/messages/message-spec.js b/lib/shared/messages/message-spec.js
--- a/lib/shared/messages/message-spec.js
+++ b/lib/shared/messages/message-spec.js
@@ -145,7 +145,7 @@
   +showInMessagePreview?: (
     messageInfo: Info,
     params: ShowInMessagePreviewParams,
-  ) => Promise<boolean>,
+  ) => boolean | Promise<boolean>,
   +getLastUpdatedTime?: (
     messageInfoOrRawMessageInfo: Info | RawInfo,
     params: ShowInMessagePreviewParams,
diff --git a/lib/shared/messages/multimedia-message-spec.js b/lib/shared/messages/multimedia-message-spec.js
--- a/lib/shared/messages/multimedia-message-spec.js
+++ b/lib/shared/messages/multimedia-message-spec.js
@@ -379,7 +379,7 @@
   validator: rawMultimediaMessageInfoValidator,
 
   showInMessagePreview: (messageInfo: MediaMessageInfo | ImagesMessageInfo) =>
-    Promise.resolve(messageInfo.media.length > 0),
+    messageInfo.media.length > 0,
 
   getLastUpdatedTime: (
     messageInfo:
diff --git a/lib/shared/messages/remove-members-message-spec.js b/lib/shared/messages/remove-members-message-spec.js
--- a/lib/shared/messages/remove-members-message-spec.js
+++ b/lib/shared/messages/remove-members-message-spec.js
@@ -235,7 +235,7 @@
       return { shouldMerge: true, item: mergedItem };
     },
 
-    showInMessagePreview: async (
+    showInMessagePreview: (
       messageInfo: RemoveMembersMessageInfo,
       params: ShowInMessagePreviewParams,
     ) => threadTypeIsThick(params.threadInfo.type),