diff --git a/pubspec.yaml b/pubspec.yaml
index c23967c..9150b69 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -9,6 +9,7 @@ environment:
 
 dependencies:
   chat_bubbles: ^1.6.0
+  collection: ^1.19.0
   flutter:
     sdk: flutter
   flutter_background: ^1.3.0+1