diff --git a/pubspec.yaml b/pubspec.yaml
index 48fa61f..e87d585 100755
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,7 +4,7 @@ description: Data dump of Dungeon World classes, moves, equipment, and more. Als
 version: 3.1.1
 
 environment:
-  sdk: ">=3.2.2"
+  sdk: ">=3.2.2 <4.0.0"
 
 dependencies:
   collection: ^1.17.0