diff --git a/README.md b/README.md
index 86b6fb3..19af7e7 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,5 @@
 An example Drupal 8 module to provide a custom "dice" field as a way of specifying a dice value such as 1d6 or 2d8+3.
 
 See http://www.ixis.co.uk/blog/drupal-8-creating-field-types-multiple-values
+
+The 10.1.x-dev branch has been tested on Drupal version 10.1.x-dev
diff --git a/dicefield.info.yml b/dicefield.info.yml
index 874244c..9d00cd5 100644
--- a/dicefield.info.yml
+++ b/dicefield.info.yml
@@ -2,8 +2,7 @@ name: Dice field
 type: module
 description: A way of specifying a dice value such as 1d6 or 2d8+3.
 package: Field types
-version: 1.0
-core: 8.x
-
+version: 2.x
+core_version_requirement: ^9.4 || ^10
 dependencies:
   - field
diff --git a/src/AverageRoll.php b/src/AverageRoll.php
index e2d3ed6..df1cbb7 100644
--- a/src/AverageRoll.php
+++ b/src/AverageRoll.php
@@ -7,7 +7,6 @@
 namespace Drupal\dicefield;
 
 use Drupal\Component\Utility\SafeMarkup;
-use Drupal\Component\Utility\String;
 use Drupal\Core\TypedData\DataDefinitionInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
 use Drupal\Core\TypedData\TypedData;