diff --git a/modules/openapi-generator/src/main/resources/php/.travis.yml b/modules/openapi-generator/src/main/resources/php/.travis.yml
index 714772ee931..667b8156530 100644
--- a/modules/openapi-generator/src/main/resources/php/.travis.yml
+++ b/modules/openapi-generator/src/main/resources/php/.travis.yml
@@ -3,7 +3,6 @@ language: php
 # https://docs.travis-ci.com/user/reference/bionic/#php-support
 dist: bionic
 php:
-    - 7.3
     - 7.4
 before_install: "composer install"
 script: "vendor/bin/phpunit"
diff --git a/modules/openapi-generator/src/main/resources/php/ApiException.mustache b/modules/openapi-generator/src/main/resources/php/ApiException.mustache
index 0410c3ed4a2..e9d6544b21c 100644
--- a/modules/openapi-generator/src/main/resources/php/ApiException.mustache
+++ b/modules/openapi-generator/src/main/resources/php/ApiException.mustache
@@ -1,7 +1,7 @@
 <?php
 /**
  * ApiException
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/Configuration.mustache b/modules/openapi-generator/src/main/resources/php/Configuration.mustache
index 408740429ae..97a464fc31f 100644
--- a/modules/openapi-generator/src/main/resources/php/Configuration.mustache
+++ b/modules/openapi-generator/src/main/resources/php/Configuration.mustache
@@ -1,7 +1,7 @@
 <?php
 /**
  * Configuration
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
@@ -20,7 +20,7 @@ namespace {{invokerPackage}};
 
 /**
  * Configuration Class Doc Comment
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache b/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
index a2622e30ed7..5d62a7b5b9d 100644
--- a/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
+++ b/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
@@ -1,7 +1,7 @@
 <?php
 /**
  * ApiException
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/ModelInterface.mustache b/modules/openapi-generator/src/main/resources/php/ModelInterface.mustache
index 417ca5d56e3..e13fc20411e 100644
--- a/modules/openapi-generator/src/main/resources/php/ModelInterface.mustache
+++ b/modules/openapi-generator/src/main/resources/php/ModelInterface.mustache
@@ -2,7 +2,7 @@
 /**
  * ModelInterface
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{modelPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache b/modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache
index 9605716bfce..123182a3331 100644
--- a/modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache
+++ b/modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache
@@ -2,7 +2,7 @@
 /**
  * ObjectSerializer
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/README.mustache b/modules/openapi-generator/src/main/resources/php/README.mustache
index 7560a358dd2..9d68414bf2c 100644
--- a/modules/openapi-generator/src/main/resources/php/README.mustache
+++ b/modules/openapi-generator/src/main/resources/php/README.mustache
@@ -12,8 +12,8 @@ For more information, please visit [{{{infoUrl}}}]({{{infoUrl}}}).
 
 ### Requirements
 
-PHP 7.3 and later.
-Should also work with PHP 8.0 or 8.1 but has not been tested.
+PHP 7.4 and later.
+Should also work with PHP 8.0.
 
 ### Composer
 
diff --git a/modules/openapi-generator/src/main/resources/php/api.mustache b/modules/openapi-generator/src/main/resources/php/api.mustache
index e1c08f2bf87..cb143c12c07 100644
--- a/modules/openapi-generator/src/main/resources/php/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api.mustache
@@ -1,7 +1,7 @@
 <?php
 /**
  * {{classname}}
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/api_test.mustache b/modules/openapi-generator/src/main/resources/php/api_test.mustache
index 6685fe5d5e0..86a534a64f5 100644
--- a/modules/openapi-generator/src/main/resources/php/api_test.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api_test.mustache
@@ -1,7 +1,7 @@
 <?php
 /**
  * {{classname}}Test
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/composer.mustache b/modules/openapi-generator/src/main/resources/php/composer.mustache
index 8b6d4e98696..274256f3e93 100644
--- a/modules/openapi-generator/src/main/resources/php/composer.mustache
+++ b/modules/openapi-generator/src/main/resources/php/composer.mustache
@@ -24,7 +24,7 @@
         }
     ],
     "require": {
-        "php": "^7.3 || ^8.0",
+        "php": "^7.4 || ^8.0",
         "ext-curl": "*",
         "ext-json": "*",
         "ext-mbstring": "*",
diff --git a/modules/openapi-generator/src/main/resources/php/model.mustache b/modules/openapi-generator/src/main/resources/php/model.mustache
index c100009e5fa..bee3f85d905 100644
--- a/modules/openapi-generator/src/main/resources/php/model.mustache
+++ b/modules/openapi-generator/src/main/resources/php/model.mustache
@@ -4,7 +4,7 @@
 /**
  * {{classname}}
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/modules/openapi-generator/src/main/resources/php/model_test.mustache b/modules/openapi-generator/src/main/resources/php/model_test.mustache
index c2fffedde4a..e9b07433988 100644
--- a/modules/openapi-generator/src/main/resources/php/model_test.mustache
+++ b/modules/openapi-generator/src/main/resources/php/model_test.mustache
@@ -4,7 +4,7 @@
 /**
  * {{classname}}Test
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  {{invokerPackage}}
diff --git a/samples/client/petstore/php/OpenAPIClient-php/.travis.yml b/samples/client/petstore/php/OpenAPIClient-php/.travis.yml
index 714772ee931..667b8156530 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/.travis.yml
+++ b/samples/client/petstore/php/OpenAPIClient-php/.travis.yml
@@ -3,7 +3,6 @@ language: php
 # https://docs.travis-ci.com/user/reference/bionic/#php-support
 dist: bionic
 php:
-    - 7.3
     - 7.4
 before_install: "composer install"
 script: "vendor/bin/phpunit"
diff --git a/samples/client/petstore/php/OpenAPIClient-php/README.md b/samples/client/petstore/php/OpenAPIClient-php/README.md
index f414f31e68e..b7cb4dd4e18 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/README.md
+++ b/samples/client/petstore/php/OpenAPIClient-php/README.md
@@ -7,8 +7,8 @@ This spec is mainly for testing Petstore server and contains fake endpoints, mod
 
 ### Requirements
 
-PHP 7.3 and later.
-Should also work with PHP 8.0 or 8.1 but has not been tested.
+PHP 7.4 and later.
+Should also work with PHP 8.0.
 
 ### Composer
 
diff --git a/samples/client/petstore/php/OpenAPIClient-php/composer.json b/samples/client/petstore/php/OpenAPIClient-php/composer.json
index b2250cf6722..6a58d7e1f04 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/composer.json
+++ b/samples/client/petstore/php/OpenAPIClient-php/composer.json
@@ -18,7 +18,7 @@
         }
     ],
     "require": {
-        "php": "^7.3 || ^8.0",
+        "php": "^7.4 || ^8.0",
         "ext-curl": "*",
         "ext-json": "*",
         "ext-mbstring": "*",
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
index 24370ac59ca..8ceccd6d1fa 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * AnotherFakeApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
index e7bb5466969..ca12028c335 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * DefaultApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
index 661502e68fa..df90fc2712a 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * FakeApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
index 2e3975bb532..2e66ebeb56a 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * FakeClassnameTags123Api
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
index d0fa9cdfc45..0597c1c394b 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * PetApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
index 6e9315b0f19..c8566c1be8d 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * StoreApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
index 06d0e62e96e..7b1c0ea506b 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * UserApi
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/ApiException.php b/samples/client/petstore/php/OpenAPIClient-php/lib/ApiException.php
index e12b7f2816c..d83029d4366 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/ApiException.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/ApiException.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * ApiException
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Configuration.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Configuration.php
index 77be482f736..9047b24cadf 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Configuration.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Configuration.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * Configuration
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
@@ -29,7 +29,7 @@ namespace OpenAPI\Client;
 
 /**
  * Configuration Class Doc Comment
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php b/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
index 627222ab36c..5364ae88f15 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * ApiException
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AdditionalPropertiesClass.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AdditionalPropertiesClass.php
index 7fe1760f7c0..5aa5ce1a3d5 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AdditionalPropertiesClass.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AdditionalPropertiesClass.php
@@ -2,7 +2,7 @@
 /**
  * AdditionalPropertiesClass
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AllOfWithSingleRef.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AllOfWithSingleRef.php
index 2e244847e6e..c7a62082070 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AllOfWithSingleRef.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/AllOfWithSingleRef.php
@@ -2,7 +2,7 @@
 /**
  * AllOfWithSingleRef
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Animal.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Animal.php
index 8124e749d76..a672435fae2 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Animal.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Animal.php
@@ -2,7 +2,7 @@
 /**
  * Animal
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ApiResponse.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ApiResponse.php
index f3b5b1f3ffa..e35aba37d59 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ApiResponse.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ApiResponse.php
@@ -2,7 +2,7 @@
 /**
  * ApiResponse
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfArrayOfNumberOnly.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfArrayOfNumberOnly.php
index 8b1c00ff915..6465985f14e 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfArrayOfNumberOnly.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfArrayOfNumberOnly.php
@@ -2,7 +2,7 @@
 /**
  * ArrayOfArrayOfNumberOnly
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfNumberOnly.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfNumberOnly.php
index fe1cb0a5cbc..8a025f24c8f 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfNumberOnly.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayOfNumberOnly.php
@@ -2,7 +2,7 @@
 /**
  * ArrayOfNumberOnly
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayTest.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayTest.php
index 6500a78c1b1..d32da689549 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayTest.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ArrayTest.php
@@ -2,7 +2,7 @@
 /**
  * ArrayTest
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Capitalization.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Capitalization.php
index 5295a9af0d6..6a486268b70 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Capitalization.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Capitalization.php
@@ -2,7 +2,7 @@
 /**
  * Capitalization
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Cat.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Cat.php
index d16497f464d..9e298157313 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Cat.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Cat.php
@@ -2,7 +2,7 @@
 /**
  * Cat
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/CatAllOf.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/CatAllOf.php
index ac1f6818ff9..5d081918955 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/CatAllOf.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/CatAllOf.php
@@ -2,7 +2,7 @@
 /**
  * CatAllOf
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Category.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Category.php
index d5dcda26b28..6906b0c16ae 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Category.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Category.php
@@ -2,7 +2,7 @@
 /**
  * Category
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ClassModel.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ClassModel.php
index da21c71d5d4..12d546ac443 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ClassModel.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ClassModel.php
@@ -2,7 +2,7 @@
 /**
  * ClassModel
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Client.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Client.php
index d3fe6e7c12a..2aa45864bd2 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Client.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Client.php
@@ -2,7 +2,7 @@
 /**
  * Client
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DeprecatedObject.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DeprecatedObject.php
index a16624c39d1..cae0381cf30 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DeprecatedObject.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DeprecatedObject.php
@@ -2,7 +2,7 @@
 /**
  * DeprecatedObject
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Dog.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Dog.php
index b5e28d06b55..3c10238d318 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Dog.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Dog.php
@@ -2,7 +2,7 @@
 /**
  * Dog
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DogAllOf.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DogAllOf.php
index 8208f92c08e..dd6e9bb5456 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DogAllOf.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/DogAllOf.php
@@ -2,7 +2,7 @@
 /**
  * DogAllOf
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumArrays.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumArrays.php
index a27207d92bd..8ffb7f5e132 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumArrays.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumArrays.php
@@ -2,7 +2,7 @@
 /**
  * EnumArrays
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumClass.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumClass.php
index 8b9e1d319f8..c513e73a58c 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumClass.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumClass.php
@@ -2,7 +2,7 @@
 /**
  * EnumClass
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumTest.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumTest.php
index 2adce4a529f..7b5054dbc50 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumTest.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/EnumTest.php
@@ -2,7 +2,7 @@
 /**
  * EnumTest
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/File.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/File.php
index 28759fd711d..cfd17fe0f94 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/File.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/File.php
@@ -2,7 +2,7 @@
 /**
  * File
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FileSchemaTestClass.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FileSchemaTestClass.php
index ee8db3b3a77..1583e558a2c 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FileSchemaTestClass.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FileSchemaTestClass.php
@@ -2,7 +2,7 @@
 /**
  * FileSchemaTestClass
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Foo.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Foo.php
index 752d3eb6f9d..9ee5179ee78 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Foo.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Foo.php
@@ -2,7 +2,7 @@
 /**
  * Foo
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FooGetDefaultResponse.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FooGetDefaultResponse.php
index 3746ab940f3..85829d08e39 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FooGetDefaultResponse.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FooGetDefaultResponse.php
@@ -2,7 +2,7 @@
 /**
  * FooGetDefaultResponse
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FormatTest.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FormatTest.php
index 8447d794be3..da50b051486 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FormatTest.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/FormatTest.php
@@ -2,7 +2,7 @@
 /**
  * FormatTest
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HasOnlyReadOnly.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HasOnlyReadOnly.php
index 070bcda1e6b..0c55dcde19b 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HasOnlyReadOnly.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HasOnlyReadOnly.php
@@ -2,7 +2,7 @@
 /**
  * HasOnlyReadOnly
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HealthCheckResult.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HealthCheckResult.php
index 52897fded0f..65aaeed0dac 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HealthCheckResult.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/HealthCheckResult.php
@@ -2,7 +2,7 @@
 /**
  * HealthCheckResult
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/InlineResponseDefault.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/InlineResponseDefault.php
index 9c19fd6a0a8..7370e252c8f 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/InlineResponseDefault.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/InlineResponseDefault.php
@@ -2,7 +2,7 @@
 /**
  * InlineResponseDefault
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MapTest.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MapTest.php
index ca11f082697..d23a6d74a0d 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MapTest.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MapTest.php
@@ -2,7 +2,7 @@
 /**
  * MapTest
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MixedPropertiesAndAdditionalPropertiesClass.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MixedPropertiesAndAdditionalPropertiesClass.php
index e3a69ea6899..805c4ffd202 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MixedPropertiesAndAdditionalPropertiesClass.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/MixedPropertiesAndAdditionalPropertiesClass.php
@@ -2,7 +2,7 @@
 /**
  * MixedPropertiesAndAdditionalPropertiesClass
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Model200Response.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Model200Response.php
index 8f5c3c6d1ca..23d254340c6 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Model200Response.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Model200Response.php
@@ -2,7 +2,7 @@
 /**
  * Model200Response
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelInterface.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelInterface.php
index b216e3f9a0a..d852155737e 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelInterface.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelInterface.php
@@ -2,7 +2,7 @@
 /**
  * ModelInterface
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client\Model
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelList.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelList.php
index 97cc7aaa612..aa59e48d9ac 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelList.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelList.php
@@ -2,7 +2,7 @@
 /**
  * ModelList
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelReturn.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelReturn.php
index 60b77d29253..d491050c7a2 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelReturn.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ModelReturn.php
@@ -2,7 +2,7 @@
 /**
  * ModelReturn
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Name.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Name.php
index 632346409b7..48ffc70baf8 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Name.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Name.php
@@ -2,7 +2,7 @@
 /**
  * Name
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NullableClass.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NullableClass.php
index f545804f713..78083265058 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NullableClass.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NullableClass.php
@@ -2,7 +2,7 @@
 /**
  * NullableClass
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NumberOnly.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NumberOnly.php
index 83a712516d1..f15bfce5ce5 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NumberOnly.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/NumberOnly.php
@@ -2,7 +2,7 @@
 /**
  * NumberOnly
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ObjectWithDeprecatedFields.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ObjectWithDeprecatedFields.php
index 0f3768b6fe4..4d306c605a2 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ObjectWithDeprecatedFields.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ObjectWithDeprecatedFields.php
@@ -2,7 +2,7 @@
 /**
  * ObjectWithDeprecatedFields
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Order.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Order.php
index 2318e4c4be1..2064c10f0ff 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Order.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Order.php
@@ -2,7 +2,7 @@
 /**
  * Order
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterComposite.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterComposite.php
index cb5dea9f9d9..28c717a8ecf 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterComposite.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterComposite.php
@@ -2,7 +2,7 @@
 /**
  * OuterComposite
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnum.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnum.php
index 6ee35cc3187..5a2351e3ed8 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnum.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnum.php
@@ -2,7 +2,7 @@
 /**
  * OuterEnum
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumDefaultValue.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumDefaultValue.php
index 30dadd3c7ea..d860d061a00 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumDefaultValue.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumDefaultValue.php
@@ -2,7 +2,7 @@
 /**
  * OuterEnumDefaultValue
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumInteger.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumInteger.php
index 0aa176d13f6..aef692f5476 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumInteger.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumInteger.php
@@ -2,7 +2,7 @@
 /**
  * OuterEnumInteger
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumIntegerDefaultValue.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumIntegerDefaultValue.php
index 622e76d0aae..6ee2a778eca 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumIntegerDefaultValue.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterEnumIntegerDefaultValue.php
@@ -2,7 +2,7 @@
 /**
  * OuterEnumIntegerDefaultValue
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterObjectWithEnumProperty.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterObjectWithEnumProperty.php
index 7a27b23ad12..8bf8552764d 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterObjectWithEnumProperty.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/OuterObjectWithEnumProperty.php
@@ -2,7 +2,7 @@
 /**
  * OuterObjectWithEnumProperty
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Pet.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Pet.php
index 50d5fabc0f0..7ab9e490064 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Pet.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Pet.php
@@ -2,7 +2,7 @@
 /**
  * Pet
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ReadOnlyFirst.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ReadOnlyFirst.php
index 53442b32dcd..3a92a68f144 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ReadOnlyFirst.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/ReadOnlyFirst.php
@@ -2,7 +2,7 @@
 /**
  * ReadOnlyFirst
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SingleRefType.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SingleRefType.php
index 398508a02ea..dc6927e77f7 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SingleRefType.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SingleRefType.php
@@ -2,7 +2,7 @@
 /**
  * SingleRefType
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SpecialModelName.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SpecialModelName.php
index 591dfe03a01..18ad681c914 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SpecialModelName.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/SpecialModelName.php
@@ -2,7 +2,7 @@
 /**
  * SpecialModelName
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Tag.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Tag.php
index e627b2dfca7..9238f77dd83 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Tag.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/Tag.php
@@ -2,7 +2,7 @@
 /**
  * Tag
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/User.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/User.php
index d1219bf6ab0..5277dfac8f7 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Model/User.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Model/User.php
@@ -2,7 +2,7 @@
 /**
  * User
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php b/samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php
index f8bacf779cb..74e6ad9e852 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php
@@ -2,7 +2,7 @@
 /**
  * ObjectSerializer
  *
- * PHP version 7.3
+ * PHP version 7.4
  *
  * @category Class
  * @package  OpenAPI\Client