diff --git a/composer.json b/composer.json
index bc842bd..11d774e 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,10 @@
     "name": "drupal/physical",
     "type": "drupal-module",
     "description": "Physical supplies such fields as physical weight and dimensions.",
-    "homepage": "http://drupal.org/project/physical",
-    "license": "GPL-2.0+",
-    "minimum-stability": "dev"
+    "homepage": "https://drupal.org/project/physical",
+    "license": "GPL-2.0-or-later",
+    "minimum-stability": "dev",
+    "require": {
+        "php": "^8.0"
+    }
 }
diff --git a/src/NumberFormatter.php b/src/NumberFormatter.php
index 3240adc..a25adaf 100644
--- a/src/NumberFormatter.php
+++ b/src/NumberFormatter.php
@@ -21,13 +21,6 @@ class NumberFormatter implements NumberFormatterInterface {
    */
   protected $numberFormatter;
 
-  /**
-   * The language manager.
-   *
-   * @var \Drupal\Core\Language\LanguageManagerInterface
-   */
-  protected $languageManager;
-
   /**
    * Constructs a new NumberFormatter object.
    *
@@ -44,7 +37,7 @@ class NumberFormatter implements NumberFormatterInterface {
   /**
    * {@inheritdoc}
    */
-  public function format($number, array $options = []) {
+  public function format(string $number, array $options = []): string {
     $default_options = [
       'use_grouping' => TRUE,
       'minimum_fraction_digits' => 0,
@@ -69,7 +62,7 @@ class NumberFormatter implements NumberFormatterInterface {
   /**
    * {@inheritdoc}
    */
-  public function parse($number) {
+  public function parse(string $number): string|bool {
     if ($this->numberFormatter) {
       $number = $this->numberFormatter->parse($number);
       // The returned number should be a string.
diff --git a/src/NumberFormatterInterface.php b/src/NumberFormatterInterface.php
index 76db066..891ffb8 100644
--- a/src/NumberFormatterInterface.php
+++ b/src/NumberFormatterInterface.php
@@ -28,7 +28,7 @@ interface NumberFormatterInterface {
    * @return string
    *   The formatted number.
    */
-  public function format($number, array $options = []);
+  public function format(string $number, array $options = []): string;
 
   /**
    * Parses the given number.
@@ -41,6 +41,6 @@ interface NumberFormatterInterface {
    * @return string|false
    *   The parsed number, or FALSE on error.
    */
-  public function parse($number);
+  public function parse(string $number): string|bool;
 
 }
diff --git a/tests/modules/physical_test/physical_test.info.yml b/tests/modules/physical_test/physical_test.info.yml
index a618a29..dd799fe 100644
--- a/tests/modules/physical_test/physical_test.info.yml
+++ b/tests/modules/physical_test/physical_test.info.yml
@@ -2,6 +2,5 @@ name: Physical Fields Test
 type: module
 description: Contains various non-specific things needed in tests.
 package: Testing
-core_version_requirement: ^9 || ^10
 dependencies:
   - physical:physical
diff --git a/tests/src/Unit/AreaTest.php b/tests/src/Unit/AreaTest.php
index eef2d58..86c4014 100644
--- a/tests/src/Unit/AreaTest.php
+++ b/tests/src/Unit/AreaTest.php
@@ -18,7 +18,7 @@ class AreaTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Area
    */
-  protected $area;
+  protected Area $area;
 
   /**
    * {@inheritdoc}
diff --git a/tests/src/Unit/LengthTest.php b/tests/src/Unit/LengthTest.php
index 2a2ae64..57fbf04 100644
--- a/tests/src/Unit/LengthTest.php
+++ b/tests/src/Unit/LengthTest.php
@@ -18,7 +18,7 @@ class LengthTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Length
    */
-  protected $length;
+  protected Length $length;
 
   /**
    * {@inheritdoc}
diff --git a/tests/src/Unit/MeasurementTest.php b/tests/src/Unit/MeasurementTest.php
index 0766c5f..b3fefa2 100644
--- a/tests/src/Unit/MeasurementTest.php
+++ b/tests/src/Unit/MeasurementTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\physical\Unit;
 
 use Drupal\physical\Length;
+use Drupal\physical\Measurement;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -18,7 +19,7 @@ class MeasurementTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Measurement
    */
-  protected $measurement;
+  protected Measurement $measurement;
 
   /**
    * {@inheritdoc}
diff --git a/tests/src/Unit/TemperatureTest.php b/tests/src/Unit/TemperatureTest.php
index 56f37c6..e3ef80a 100644
--- a/tests/src/Unit/TemperatureTest.php
+++ b/tests/src/Unit/TemperatureTest.php
@@ -18,21 +18,21 @@ class TemperatureTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Temperature
    */
-  protected $temperatureKelvin;
+  protected Temperature $temperatureKelvin;
 
   /**
    * The Celsius temperature.
    *
    * @var \Drupal\physical\Temperature
    */
-  protected $temperatureCelsius;
+  protected Temperature $temperatureCelsius;
 
   /**
    * The Fahrenheit temperature.
    *
    * @var \Drupal\physical\Temperature
    */
-  protected $temperatureFahrenheit;
+  protected Temperature $temperatureFahrenheit;
 
   /**
    * {@inheritdoc}
diff --git a/tests/src/Unit/VolumeTest.php b/tests/src/Unit/VolumeTest.php
index 113392b..8150ddd 100644
--- a/tests/src/Unit/VolumeTest.php
+++ b/tests/src/Unit/VolumeTest.php
@@ -18,7 +18,7 @@ class VolumeTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Volume
    */
-  protected $volume;
+  protected Volume $volume;
 
   /**
    * {@inheritdoc}
diff --git a/tests/src/Unit/WeightTest.php b/tests/src/Unit/WeightTest.php
index 83710a3..f299502 100644
--- a/tests/src/Unit/WeightTest.php
+++ b/tests/src/Unit/WeightTest.php
@@ -18,7 +18,7 @@ class WeightTest extends UnitTestCase {
    *
    * @var \Drupal\physical\Weight
    */
-  protected $weight;
+  protected Weight $weight;
 
   /**
    * {@inheritdoc}