diff --git a/pubspec.yaml b/pubspec.yaml
index 8a312fa..334b82f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ description: A new Flutter project.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.6"
 
 dependencies:
   flutter_bluetooth_serial: ^0.2.2