diff --git a/pubspec.yaml b/pubspec.yaml
index 5d87aa9..fa2f349 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,7 +5,7 @@ publish_to: 'none'
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.12.0-0 <3.0.0'
+  sdk: '<4.0.0'
 
 dependencies:
   flutter: