diff --git a/packages/stream_chat_flutter/CHANGELOG.md b/packages/stream_chat_flutter/CHANGELOG.md
index 9e4f2744..d5e21c54 100644
--- a/packages/stream_chat_flutter/CHANGELOG.md
+++ b/packages/stream_chat_flutter/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 -[[#687]](https://github.com/GetStream/stream-chat-flutter/issues/687): Fix Users losing their place in the conversation after replying in threads.
 - Fixed floating date stream subscription causing "Bad state: stream has already been listened.” error.
+- Fixed `String` capitalize extension not working on empty strings.
 
 ✅ Added
 
diff --git a/packages/stream_chat_flutter/lib/src/extension.dart b/packages/stream_chat_flutter/lib/src/extension.dart
index 9551a40d..0072a811 100644
--- a/packages/stream_chat_flutter/lib/src/extension.dart
+++ b/packages/stream_chat_flutter/lib/src/extension.dart
@@ -12,7 +12,7 @@ final _emojiChars = Emoji.chars();
 extension StringExtension on String {
   /// Returns the capitalized string
   String capitalize() =>
-      '${this[0].toUpperCase()}${substring(1).toLowerCase()}';
+      isNotEmpty ? '${this[0].toUpperCase()}${substring(1).toLowerCase()}' : '';
 
   /// Returns whether the string contains only emoji's or not.
   ///