diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 651be1b..26c80e9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,15 +14,15 @@ concurrency:
 jobs:
   check_composer:
     name: Check composer.json
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.2'
+          php-version: '8.5'
           coverage: none
 
       - name: Validate composer.json
@@ -34,11 +34,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4', '8.5']
         min_stability: ['']
         name_suffix: ['']
         include:
-          - php: '8.3'
+          - php: '8.5'
             min_stability: 'dev'
             name_suffix: ' (dev deps)'
 
@@ -46,7 +46,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
diff --git a/CHANGES.md b/CHANGES.md
index e56458a..b6fb637 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,6 +2,18 @@
 
 * Add support for PHP 5.6
 
+# 2.5.0
+
+* Add support for PHPUnit 13
+* Add a CI job running on PHP 8.5
+
+# 2.4.0
+* Add support for PHPUnit 12
+
+# 2.3.0
+
+* changes unmerged
+
 # 2.2.0
 
 * Add support for PHPUnit 11
diff --git a/composer.json b/composer.json
index a12298d..a605d7d 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     "require": {
         "php": "^5.6 || ^7 || ^8",
         "phpspec/prophecy": "^1.3",
-        "phpunit/phpunit": "^5.0 || ^6.0 || ^7.0 || ^8.0 || ^9.0 || ^10.0 || ^11.0"
+        "phpunit/phpunit": "^5.0 || ^6.0 || ^7.0 || ^8.0 || ^9.0 || ^10.0 || ^11.0 || ^12.0 || ^13.0"
     },
     "autoload": {
         "psr-4": {
@@ -31,5 +31,8 @@
         "branch-alias": {
             "dev-master": "3.x-dev"
         }
+    },
+    "config": {
+        "sort-packages": true
     }
 }
diff --git a/src/ProphecyTrait5.php b/src/ProphecyTrait5.php
index 7f42a1a..2352368 100644
--- a/src/ProphecyTrait5.php
+++ b/src/ProphecyTrait5.php
@@ -85,6 +85,7 @@ protected function verifyProphecyDoubles()
     private function countProphecyAssertions()
     {
         \assert($this instanceof TestCase);
+        \assert($this->prophet !== null);
 
         foreach ($this->prophet->getProphecies() as $objectProphecy) {
             foreach ($objectProphecy->getMethodProphecies() as $methodProphecies) {
diff --git a/src/ProphecyTrait7.php b/src/ProphecyTrait7.php
index e6beb23..175a73d 100644
--- a/src/ProphecyTrait7.php
+++ b/src/ProphecyTrait7.php
@@ -85,6 +85,7 @@ protected function verifyProphecyDoubles()
     private function countProphecyAssertions()/*: void*/
     {
         \assert($this instanceof TestCase);
+        \assert($this->prophet !== null);
 
         foreach ($this->prophet->getProphecies() as $objectProphecy) {
             foreach ($objectProphecy->getMethodProphecies() as $methodProphecies) {