diff --git a/pubspec.yaml b/pubspec.yaml
index 934fbb2..7e169e7 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ description: A mobile client for FileBin.
 version: 1.6.2+20
 
 environment:
-    sdk: '>=2.19.4 <3.0.0'
+    sdk: '<4.0.0'
 
 dependencies:
     flutter: