diff --git a/modules/swagger-codegen/src/main/resources/php/api.mustache b/modules/swagger-codegen/src/main/resources/php/api.mustache
index 1768ff7ac5e..bfbb6fca373 100644
--- a/modules/swagger-codegen/src/main/resources/php/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/php/api.mustache
@@ -49,7 +49,6 @@ use \{{invokerPackage}}\ObjectSerializer;
     {
         if ($apiClient === null) {
             $apiClient = new ApiClient();
-            $apiClient->getConfig()->setHost('{{basePath}}');
         }
 
         $this->apiClient = $apiClient;
diff --git a/samples/client/petstore/php/SwaggerClient-php/docs/Api/PetApi.md b/samples/client/petstore/php/SwaggerClient-php/docs/Api/PetApi.md
index b589c11a32a..d99eea4c925 100644
--- a/samples/client/petstore/php/SwaggerClient-php/docs/Api/PetApi.md
+++ b/samples/client/petstore/php/SwaggerClient-php/docs/Api/PetApi.md
@@ -389,7 +389,7 @@ Name | Type | Description  | Notes
 ------------- | ------------- | ------------- | -------------
  **pet_id** | **int**| ID of pet to update |
  **additional_metadata** | **string**| Additional data to pass to server | [optional]
- **file** | **\SplFileObject****\SplFileObject**| file to upload | [optional]
+ **file** | **\SplFileObject**| file to upload | [optional]
 
 ### Return type
 
diff --git a/samples/client/petstore/php/SwaggerClient-php/docs/Model/ClassModel.md b/samples/client/petstore/php/SwaggerClient-php/docs/Model/ClassModel.md
new file mode 100644
index 00000000000..3ad025b6ed3
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/docs/Model/ClassModel.md
@@ -0,0 +1,10 @@
+# ClassModel
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**_class** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+
diff --git a/samples/client/petstore/php/SwaggerClient-php/docs/Model/OuterEnum.md b/samples/client/petstore/php/SwaggerClient-php/docs/Model/OuterEnum.md
new file mode 100644
index 00000000000..06d413b0168
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/docs/Model/OuterEnum.md
@@ -0,0 +1,9 @@
+# OuterEnum
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php b/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
index 9d13660091f..54522e7a792 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
@@ -59,7 +59,6 @@ public function __construct(\Swagger\Client\ApiClient $apiClient = null)
     {
         if ($apiClient === null) {
             $apiClient = new ApiClient();
-            $apiClient->getConfig()->setHost('http://petstore.swagger.io/v2');
         }
 
         $this->apiClient = $apiClient;
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Api/PetApi.php b/samples/client/petstore/php/SwaggerClient-php/lib/Api/PetApi.php
index efee25ca687..cb902068dd4 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Api/PetApi.php
@@ -59,7 +59,6 @@ public function __construct(\Swagger\Client\ApiClient $apiClient = null)
     {
         if ($apiClient === null) {
             $apiClient = new ApiClient();
-            $apiClient->getConfig()->setHost('http://petstore.swagger.io/v2');
         }
 
         $this->apiClient = $apiClient;
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Api/StoreApi.php b/samples/client/petstore/php/SwaggerClient-php/lib/Api/StoreApi.php
index 7070313661d..61531c1ada4 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Api/StoreApi.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Api/StoreApi.php
@@ -59,7 +59,6 @@ public function __construct(\Swagger\Client\ApiClient $apiClient = null)
     {
         if ($apiClient === null) {
             $apiClient = new ApiClient();
-            $apiClient->getConfig()->setHost('http://petstore.swagger.io/v2');
         }
 
         $this->apiClient = $apiClient;
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Api/UserApi.php b/samples/client/petstore/php/SwaggerClient-php/lib/Api/UserApi.php
index db404dd8818..31580e1b3c1 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Api/UserApi.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Api/UserApi.php
@@ -59,7 +59,6 @@ public function __construct(\Swagger\Client\ApiClient $apiClient = null)
     {
         if ($apiClient === null) {
             $apiClient = new ApiClient();
-            $apiClient->getConfig()->setHost('http://petstore.swagger.io/v2');
         }
 
         $this->apiClient = $apiClient;
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/ApiClient.php b/samples/client/petstore/php/SwaggerClient-php/lib/ApiClient.php
index 8bda07de03f..51935028b00 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/ApiClient.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/ApiClient.php
@@ -163,6 +163,11 @@ public function callApi($resourcePath, $method, $queryParams, $postData, $header
         if ($this->config->getCurlTimeout() !== 0) {
             curl_setopt($curl, CURLOPT_TIMEOUT, $this->config->getCurlTimeout());
         }
+        // set connect timeout, if needed
+        if ($this->config->getCurlConnectTimeout() != 0) {
+            curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, $this->config->getCurlConnectTimeout());
+        }
+        
         // return the result on success, rather than just true
         curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
 
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Configuration.php b/samples/client/petstore/php/SwaggerClient-php/lib/Configuration.php
index ca4e62be7ee..8066ae8ac66 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Configuration.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Configuration.php
@@ -97,6 +97,13 @@ class Configuration
      */
     protected $curlTimeout = 0;
 
+    /**
+     * Timeout (second) of the HTTP connection, by default set to 0, no timeout
+     *
+     * @var string
+     */
+    protected $curlConnectTimeout = 0;
+
     /**
      * User agent of the HTTP request, set to "PHP-Swagger" by default
      *
@@ -380,6 +387,33 @@ public function getCurlTimeout()
         return $this->curlTimeout;
     }
 
+    /**
+     * Sets the HTTP connect timeout value
+     *
+     * @param integer $seconds Number of seconds before connection times out [set to 0 for no timeout]
+     *
+     * @return Configuration
+     */
+    public function setCurlConnectTimeout($seconds)
+    {
+        if (!is_numeric($seconds) || $seconds < 0) {
+            throw new \InvalidArgumentException('Connect timeout value must be numeric and a non-negative number.');
+        }
+
+        $this->curlConnectTimeout = $seconds;
+        return $this;
+    }
+
+    /**
+     * Gets the HTTP connect timeout value
+     *
+     * @return string HTTP connect timeout value
+     */
+    public function getCurlConnectTimeout()
+    {
+        return $this->curlConnectTimeout;
+    }
+
     /**
      * Sets debug flag
      *
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/ClassModel.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ClassModel.php
new file mode 100644
index 00000000000..74b0aff6da0
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ClassModel.php
@@ -0,0 +1,229 @@
+<?php
+/**
+ * ClassModel
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Client
+ * @author   Swaagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * OpenAPI spec version: 1.0.0
+ * Contact: apiteam@swagger.io
+ * Generated by: https://github.com/swagger-api/swagger-codegen.git
+ *
+ */
+
+/**
+ * NOTE: This class is auto generated by the swagger code generator program.
+ * https://github.com/swagger-api/swagger-codegen
+ * Do not edit the class manually.
+ */
+
+namespace Swagger\Client\Model;
+
+use \ArrayAccess;
+
+/**
+ * ClassModel Class Doc Comment
+ *
+ * @category    Class */
+ // @description Model for testing model with \&quot;_class\&quot; property
+/**
+ * @package     Swagger\Client
+ * @author      Swagger Codegen team
+ * @link        https://github.com/swagger-api/swagger-codegen
+ */
+class ClassModel implements ArrayAccess
+{
+    const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      * @var string
+      */
+    protected static $swaggerModelName = 'ClassModel';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      * @var string[]
+      */
+    protected static $swaggerTypes = [
+        '_class' => 'string'
+    ];
+
+    public static function swaggerTypes()
+    {
+        return self::$swaggerTypes;
+    }
+
+    /**
+     * Array of attributes where the key is the local name, and the value is the original name
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        '_class' => '_class'
+    ];
+
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     * @var string[]
+     */
+    protected static $setters = [
+        '_class' => 'setClass'
+    ];
+
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     * @var string[]
+     */
+    protected static $getters = [
+        '_class' => 'getClass'
+    ];
+
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    
+
+    
+
+    /**
+     * Associative array for storing property values
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     * @param mixed[] $data Associated array of property values initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->container['_class'] = isset($data['_class']) ? $data['_class'] : null;
+    }
+
+    /**
+     * show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalid_properties = [];
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properteis are valid
+     */
+    public function valid()
+    {
+        return true;
+    }
+
+
+    /**
+     * Gets _class
+     * @return string
+     */
+    public function getClass()
+    {
+        return $this->container['_class'];
+    }
+
+    /**
+     * Sets _class
+     * @param string $_class
+     * @return $this
+     */
+    public function setClass($_class)
+    {
+        $this->container['_class'] = $_class;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     * @param  integer $offset Offset
+     * @return boolean
+     */
+    public function offsetExists($offset)
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     * @param  integer $offset Offset
+     * @return mixed
+     */
+    public function offsetGet($offset)
+    {
+        return isset($this->container[$offset]) ? $this->container[$offset] : null;
+    }
+
+    /**
+     * Sets value based on offset.
+     * @param  integer $offset Offset
+     * @param  mixed   $value  Value to be set
+     * @return void
+     */
+    public function offsetSet($offset, $value)
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     * @param  integer $offset Offset
+     * @return void
+     */
+    public function offsetUnset($offset)
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     * @return string
+     */
+    public function __toString()
+    {
+        if (defined('JSON_PRETTY_PRINT')) { // use JSON pretty print
+            return json_encode(\Swagger\Client\ObjectSerializer::sanitizeForSerialization($this), JSON_PRETTY_PRINT);
+        }
+
+        return json_encode(\Swagger\Client\ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/OuterEnum.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/OuterEnum.php
new file mode 100644
index 00000000000..26c54fd1b2e
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/OuterEnum.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * OuterEnum
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Client
+ * @author   Swaagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * OpenAPI spec version: 1.0.0
+ * Contact: apiteam@swagger.io
+ * Generated by: https://github.com/swagger-api/swagger-codegen.git
+ *
+ */
+
+/**
+ * NOTE: This class is auto generated by the swagger code generator program.
+ * https://github.com/swagger-api/swagger-codegen
+ * Do not edit the class manually.
+ */
+
+namespace Swagger\Client\Model;
+
+use \ArrayAccess;
+
+/**
+ * OuterEnum Class Doc Comment
+ *
+ * @category    Class */
+/**
+ * @package     Swagger\Client
+ * @author      Swagger Codegen team
+ * @link        https://github.com/swagger-api/swagger-codegen
+ */
+class OuterEnum {
+    const PLACED = 'placed';
+    const APPROVED = 'approved';
+    const DELIVERED = 'delivered';
+    
+
+    
+}
+
diff --git a/samples/client/petstore/php/SwaggerClient-php/test/Model/ClassModelTest.php b/samples/client/petstore/php/SwaggerClient-php/test/Model/ClassModelTest.php
new file mode 100644
index 00000000000..10f290f16ed
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/test/Model/ClassModelTest.php
@@ -0,0 +1,93 @@
+<?php
+/**
+ * ClassModelTest
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Client
+ * @author   Swagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * OpenAPI spec version: 1.0.0
+ * Contact: apiteam@swagger.io
+ * Generated by: https://github.com/swagger-api/swagger-codegen.git
+ *
+ */
+
+/**
+ * NOTE: This class is auto generated by the swagger code generator program.
+ * https://github.com/swagger-api/swagger-codegen
+ * Please update the test case below to test the model.
+ */
+
+namespace Swagger\Client;
+
+/**
+ * ClassModelTest Class Doc Comment
+ *
+ * @category    Class */
+// * @description Model for testing model with \&quot;_class\&quot; property
+/**
+ * @package     Swagger\Client
+ * @author      Swagger Codegen team
+ * @link        https://github.com/swagger-api/swagger-codegen
+ */
+class ClassModelTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass()
+    {
+
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp()
+    {
+
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown()
+    {
+
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass()
+    {
+
+    }
+
+    /**
+     * Test "ClassModel"
+     */
+    public function testClassModel()
+    {
+
+    }
+
+    /**
+     * Test attribute "_class"
+     */
+    public function testPropertyClass()
+    {
+
+    }
+
+}
diff --git a/samples/client/petstore/php/SwaggerClient-php/test/Model/OuterEnumTest.php b/samples/client/petstore/php/SwaggerClient-php/test/Model/OuterEnumTest.php
new file mode 100644
index 00000000000..f053305b848
--- /dev/null
+++ b/samples/client/petstore/php/SwaggerClient-php/test/Model/OuterEnumTest.php
@@ -0,0 +1,85 @@
+<?php
+/**
+ * OuterEnumTest
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Client
+ * @author   Swagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * OpenAPI spec version: 1.0.0
+ * Contact: apiteam@swagger.io
+ * Generated by: https://github.com/swagger-api/swagger-codegen.git
+ *
+ */
+
+/**
+ * NOTE: This class is auto generated by the swagger code generator program.
+ * https://github.com/swagger-api/swagger-codegen
+ * Please update the test case below to test the model.
+ */
+
+namespace Swagger\Client;
+
+/**
+ * OuterEnumTest Class Doc Comment
+ *
+ * @category    Class */
+// * @description OuterEnum
+/**
+ * @package     Swagger\Client
+ * @author      Swagger Codegen team
+ * @link        https://github.com/swagger-api/swagger-codegen
+ */
+class OuterEnumTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass()
+    {
+
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp()
+    {
+
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown()
+    {
+
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass()
+    {
+
+    }
+
+    /**
+     * Test "OuterEnum"
+     */
+    public function testOuterEnum()
+    {
+
+    }
+
+}
diff --git a/samples/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php b/samples/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php
index fa3733a8be2..bad55050ece 100644
--- a/samples/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php
+++ b/samples/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php
@@ -479,4 +479,20 @@ public function testDefaultValues()
         $this->assertSame('red', $dog->getColor());
         $this->assertSame('red', $animal->getColor());
     }
+
+    // Ensure that API Classes pickup ApiClient defaults to prevent regressions of PR #4525
+    public function testHostOverride()
+    {
+        $orig_default = Configuration::getDefaultConfiguration();
+        $new_default  = new Configuration();
+        
+        $new_default->setHost("http://localhost/whatever");
+        Configuration::setDefaultConfiguration($new_default);
+
+        $pet_api  = new Api\PetApi();
+        $pet_host = $pet_api->getApiClient()->getConfig()->getHost();
+        $this->assertSame($pet_host, $new_default->getHost());
+
+        Configuration::setDefaultConfiguration($orig_default); // Reset to original to prevent failure of other tests that rely on this state
+    }
 }