diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index c4d38c1..e75bdda 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -18,7 +18,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: '<4.0.0'
 
 dependencies:
   listenable_stream: