diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index b536a5e..72f0c13 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -18,7 +18,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: '>=3.2.6 <4.0.0'
+  sdk: ">=2.12.0 <4.0.0"
 
 dependencies:
   flutter:
diff --git a/pubspec.yaml b/pubspec.yaml
index fae33eb..6860d6f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,12 +4,13 @@ version: 0.3.5
 homepage: https://github.com/h65wang/flutter-interactive-chart
 
 environment:
-  sdk: '>=3.2.6 <4.0.0'
+  sdk: ">=2.12.0 <4.0.0"
+  flutter: ">=1.17.0"
 
 dependencies:
   flutter:
     sdk: flutter
-  intl: ^0.19.0
+  intl: ">=0.17.0 <0.20.0"
 
 dev_dependencies:
   flutter_test: