diff --git a/pubspec.yaml b/pubspec.yaml
index 0e38d0a..6770797 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,7 +4,7 @@ version: 1.4.2
 homepage: https://github.com/FilledStacks/stacked/tree/master/packages/stacked_shared
 
 environment:
-  sdk: '>=2.16.2 <3.0.0'
+  sdk: '<4.0.0'
 
 
 dependencies: