diff --git a/pubspec.yaml b/pubspec.yaml
index 799529a..5c99d0b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,9 +4,9 @@ description: Validate Swedish organization numbers with Dart and Flutter.
 homepage: https://github.com/organisationsnummer/dart
 
 environment:
-  sdk: '>=2.18.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dev_dependencies:
-  test: ^1.22.2
+  test: ^1.20.1
 dependencies:
   personnummer: ^3.0.5