diff --git a/check_urls/pubspec.yaml b/check_urls/pubspec.yaml
index 20e8105..204e6b0 100644
--- a/check_urls/pubspec.yaml
+++ b/check_urls/pubspec.yaml
@@ -3,7 +3,7 @@ description: Check if the urls in README.md are valid
 version: 1.0.0
 
 environment:
-  sdk: '>=2.14.0 <3.0.0'
+  sdk: '<4.0.0'
 
 dependencies:
   http: 1.2.1
\ No newline at end of file