diff --git a/lib/shared/message-utils.js b/lib/shared/message-utils.js
--- a/lib/shared/message-utils.js
+++ b/lib/shared/message-utils.js
@@ -19,19 +19,17 @@
 import { type PlatformDetails } from '../types/device-types.js';
 import type { Media } from '../types/media-types.js';
 import { messageTypes } from '../types/message-types-enum.js';
-import {
-  type ComposableMessageInfo,
-  type MessageData,
-  type MessageInfo,
-  type MessageStore,
-  type MessageTruncationStatus,
-  messageTruncationStatus,
-  type MultimediaMessageData,
-  type RawComposableMessageInfo,
-  type RawMessageInfo,
-  type RawMultimediaMessageInfo,
-  type RobotextMessageInfo,
-  type ThreadMessageInfo,
+import type {
+  ComposableMessageInfo,
+  MessageData,
+  MessageInfo,
+  MessageStore,
+  MultimediaMessageData,
+  RawComposableMessageInfo,
+  RawMessageInfo,
+  RawMultimediaMessageInfo,
+  RobotextMessageInfo,
+  ThreadMessageInfo,
 } from '../types/message-types.js';
 import type {
   EditMessageInfo,
@@ -196,26 +194,6 @@
   return [...userIDs];
 }
 
-function combineTruncationStatuses(
-  first: MessageTruncationStatus,
-  second: ?MessageTruncationStatus,
-): MessageTruncationStatus {
-  if (
-    first === messageTruncationStatus.EXHAUSTIVE ||
-    second === messageTruncationStatus.EXHAUSTIVE
-  ) {
-    return messageTruncationStatus.EXHAUSTIVE;
-  } else if (
-    first === messageTruncationStatus.UNCHANGED &&
-    second !== null &&
-    second !== undefined
-  ) {
-    return second;
-  } else {
-    return first;
-  }
-}
-
 function shimUnsupportedRawMessageInfos(
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   platformDetails: ?PlatformDetails,
@@ -707,7 +685,6 @@
   rawMessageInfoFromMessageData,
   mostRecentMessageTimestamp,
   usersInMessageInfos,
-  combineTruncationStatuses,
   shimUnsupportedRawMessageInfos,
   createMediaMessageData,
   createMediaMessageInfo,
diff --git a/lib/shared/truncation-utils.js b/lib/shared/truncation-utils.js
new file mode 100644
--- /dev/null
+++ b/lib/shared/truncation-utils.js
@@ -0,0 +1,28 @@
+// @flow
+
+import {
+  type MessageTruncationStatus,
+  messageTruncationStatus,
+} from '../types/message-types.js';
+
+function combineTruncationStatuses(
+  first: MessageTruncationStatus,
+  second: ?MessageTruncationStatus,
+): MessageTruncationStatus {
+  if (
+    first === messageTruncationStatus.EXHAUSTIVE ||
+    second === messageTruncationStatus.EXHAUSTIVE
+  ) {
+    return messageTruncationStatus.EXHAUSTIVE;
+  } else if (
+    first === messageTruncationStatus.UNCHANGED &&
+    second !== null &&
+    second !== undefined
+  ) {
+    return second;
+  } else {
+    return first;
+  }
+}
+
+export { combineTruncationStatuses };
diff --git a/lib/shared/updates/join-thread-spec.js b/lib/shared/updates/join-thread-spec.js
--- a/lib/shared/updates/join-thread-spec.js
+++ b/lib/shared/updates/join-thread-spec.js
@@ -26,8 +26,8 @@
   ThreadJoinUpdateData,
 } from '../../types/update-types.js';
 import { tNumber, tShape } from '../../utils/validation-utils.js';
-import { combineTruncationStatuses } from '../message-utils.js';
 import { threadInFilterList } from '../thread-utils.js';
+import { combineTruncationStatuses } from '../truncation-utils.js';
 
 export const joinThreadSpec: UpdateSpec<
   ThreadJoinUpdateInfo,