Updated dependencies to remove pre-release warnings from pub publish.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93975ad..840f689 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,15 @@
 Changelog
 =========
 
+#### Version 3.1.1 (2021-06-04)
+
+* Updated pubspec
+
 #### Version 3.1.0 (2021-05-31)
 
 * SRP support
 * Readme correction
+* not published
 
 #### Version 3.0.1 (2021-03-24)
 
diff --git a/pubspec.yaml b/pubspec.yaml
index aa55322..df0184b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,12 +1,13 @@
 name: pointycastle
-version: 3.1.0
+version: 3.1.1
 description: A Dart library implementing cryptographic algorithms and primitives, modeled on the BouncyCastle library.
 homepage: https://github.com/bcgit/pc-dart
 environment:
-  sdk: '>=2.12.0-0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
-  collection: ^1.15.0-nullsafety.4
+  collection: ^1.15.0
+  convert: ^3.0.0
 
 dev_dependencies:
   benchmark_harness:  ^2.0.0-nullsafety