diff --git a/pubspec.yaml b/pubspec.yaml
index f16f3f2..4fbd02e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -9,7 +9,7 @@ publish_to: 'none'
 version: 1.9.0+30
 
 environment:
-  sdk: ">=2.18.2 <3.0.0"
+  sdk: "<4.0.0"
 
 dependencies:
   canteenlib: ^1.1.4