diff --git a/SignalUtilitiesKit/Utilities/ThreadUtil.m b/SignalUtilitiesKit/Utilities/ThreadUtil.m
index 62a5963fe..bb191b0db 100644
--- a/SignalUtilitiesKit/Utilities/ThreadUtil.m
+++ b/SignalUtilitiesKit/Utilities/ThreadUtil.m
@@ -169,6 +169,12 @@ NS_ASSUME_NONNULL_BEGIN
     // the messages view the position of the unread indicator,
     // so that it can widen its "load window" to always show
     // the unread indicator.
+    //
+    // We'll load all of the unread messages. This number may be larger
+    // than the maxRangeSize. This is not the idealest solution for the
+    // crash when unread message number is over 100. We can do better if
+    // we just load maxRangeSize number of unread messages, but the unread
+    // indicator can still be at the correct position.
     __block long visibleUnseenMessageCount = 0;
     __block TSInteraction *interactionAfterUnreadIndicator = nil;
     __block BOOL hasMoreUnseenMessages = NO;