diff --git a/.github/workflows/lint54.yml b/.github/workflows/lint54.yml
deleted file mode 100644
index bb47dd9..0000000
--- a/.github/workflows/lint54.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-name: Lint PHP 5.4
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v2
-
-    - name: Install PHP
-      uses: shivammathur/setup-php@v2
-      with:
-        php-version: '5.4'
-
-    - name: Lint
-      run: find lib/ -name \*.php -exec sh -c 'php -l "$0" || kill $PPID' \{\} \;
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 17f3707..6edc73f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,21 +2,49 @@ name: Run tests
 
 on:
   push:
-    branches: [ master ]
+    branches:
+    tags:
   pull_request:
-    branches: [ master ]
+    branches:
 
 jobs:
   build:
-
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        php: [7.3, 7.4, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5]
+        os: [ubuntu-latest]
+    name: PHP ${{ matrix.php }} Test on ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v6
+
+    - name: Install PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: ${{ matrix.php }}
+        extensions: json
+        ini-values: zend.assertions=1, error_reporting=E_ALL
+        coverage: none
+
+    - name: PHP lint
+      run: find lib/ -name \*.php -exec sh -c 'php -l "$0" || kill $PPID' \{\} \;
 
     - name: Validate composer.json and composer.lock
       run: composer validate
 
+    - name: Get composer cache directory
+      id: composer-cache
+      run: echo "COMPOSER_CACHE_DIR=$(composer config cache-files-dir)" >> "$GITHUB_OUTPUT"
+
+    - name: Cache dependencies
+      uses: actions/cache@v6
+      with:
+        path: ${{ steps.composer-cache.outputs.COMPOSER_CACHE_DIR }}
+        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
+        restore-keys: ${{ runner.os }}-composer-
+
     - name: Install dependencies
       run: composer install --prefer-dist --no-progress --no-suggest
 
diff --git a/Makefile b/Makefile
index 7387fce..3f186c2 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,11 @@
 
 generate:
 	php vendor/bin/jane-openapi generate --config-file=jane-openapi-configuration.php
-	rm -rf lib/Generated/{Authentication,Endpoint,Normalizer,Client.php,Runtime}
+	@rm -rf lib/Generated/Authentication/
+	@rm -rf lib/Generated/Endpoint/
+	@rm -rf lib/Generated/Normalizer/
+	@rm -rf lib/Generated/Client.php
+	@rm -rf lib/Generated/Runtime/
 
 test:
 	@./vendor/bin/phpunit -d date.timezone=Europe/Moscow tests/ --colors=always
diff --git a/composer.json b/composer.json
index e2a7dbe..1e2c1d3 100644
--- a/composer.json
+++ b/composer.json
@@ -3,13 +3,17 @@
     "description": "PHP SDK for MAXMA API",
     "type": "library",
     "require": {
-        "php": ">= 5.4",
+        "php": ">= 7.3",
         "ext-json": "*"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^2.16",
         "phpunit/phpunit": "^9.5",
-        "jane-php/open-api-3": "^7.2",
+        "jane-php/json-schema": "7.3.*",
+        "jane-php/json-schema-runtime": "7.3.*",
+        "jane-php/open-api-3": "7.3.*",
+        "jane-php/open-api-common": "7.3.*",
+        "jane-php/open-api-runtime": "7.3.*",
         "guzzlehttp/guzzle": "^7.4",
         "symfony/translation-contracts": "^2.5",
         "psr/log": "^1.1",
@@ -28,5 +32,10 @@
             "Tools\\": "tools/",
             "Tests\\": "tests/"
         }
+    },
+    "config": {
+        "allow-plugins": {
+            "php-http/discovery": true
+        }
     }
 }
diff --git a/lib/Client.php b/lib/Client.php
index fe0d9ae..6d3141a 100644
--- a/lib/Client.php
+++ b/lib/Client.php
@@ -146,9 +146,9 @@ class Client
 
     public function __construct(
         array $config = [],
-        ClientInterface $httpClient = null,
-        SerializerInterface $serializer = null,
-        LoggerInterface $logger = null
+        ?ClientInterface $httpClient = null,
+        ?SerializerInterface $serializer = null,
+        ?LoggerInterface $logger = null
     ) {
         if (isset($config['serverAddress'])) {
             $this->setServerAddress($config['serverAddress']);
diff --git a/lib/Generated/Model/ClientOfferCounter.php b/lib/Generated/Model/ClientOfferCounter.php
index 332b3cb..49b3900 100644
--- a/lib/Generated/Model/ClientOfferCounter.php
+++ b/lib/Generated/Model/ClientOfferCounter.php
@@ -32,7 +32,7 @@ class ClientOfferCounter
     protected $targetValue;
 
     /**
-     * Дата, до которой нужно накопить счетчик
+     * Дата, до которой нужно накопить счетчик. Поле не возвращается, если срок не задан.
      *
      * @var \DateTime|null
      */
@@ -115,7 +115,7 @@ public function setTargetValue($targetValue)
     }
 
     /**
-     * Дата, до которой нужно накопить счетчик
+     * Дата, до которой нужно накопить счетчик. Поле не возвращается, если срок не задан.
      *
      * @return \DateTime|null
      */
@@ -125,13 +125,13 @@ public function getTargetDate()
     }
 
     /**
-     * Дата, до которой нужно накопить счетчик
+     * Дата, до которой нужно накопить счетчик. Поле не возвращается, если срок не задан.
      *
      * @param \DateTime|null $targetDate
      *
      * @return self
      */
-    public function setTargetDate(\DateTime $targetDate = null)
+    public function setTargetDate(?\DateTime $targetDate = null)
     {
         $this->targetDate = $targetDate;
         return $this;
@@ -159,4 +159,4 @@ public function setCoupons($coupons)
         $this->coupons = $coupons;
         return $this;
     }
-}
+}
\ No newline at end of file
diff --git a/tools/Fixer/RemoveTypeHintFixer.php b/tools/Fixer/RemoveTypeHintFixer.php
index d94154a..733830c 100644
--- a/tools/Fixer/RemoveTypeHintFixer.php
+++ b/tools/Fixer/RemoveTypeHintFixer.php
@@ -72,10 +72,10 @@ public function fix(\SplFileInfo $file, Tokens $tokens)
             foreach ($arguments as $argumentInfo) {
                 $ta = $argumentInfo->getTypeAnalysis();
                 if ($ta) {
-                    // Remove ?
                     if ($ta->isNullable()) {
-                        $tokens->removeTrailingWhitespace($ta->getStartIndex());
-                        $tokens->clearTokenAndMergeSurroundingWhitespace($ta->getStartIndex());
+                        // These lines will remove ? nullable type definition
+                        //$tokens->removeTrailingWhitespace($ta->getStartIndex());
+                        //$tokens->clearTokenAndMergeSurroundingWhitespace($ta->getStartIndex());
                         $defaultNullUntilEnd = true;
                     }