diff --git a/modules/openapi-generator/src/main/resources/php/api.mustache b/modules/openapi-generator/src/main/resources/php/api.mustache
index 537cf815951b..2014b8ec83bd 100644
--- a/modules/openapi-generator/src/main/resources/php/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api.mustache
@@ -472,11 +472,22 @@ use {{invokerPackage}}\ObjectSerializer;
         $multipart = false;
 
         {{#queryParams}}
-
         // query params
         {{#isExplode}}
         if (${{paramName}} !== null) {
+        {{#style}}
+            if('form' === '{{style}}' && is_array(${{paramName}})) {
+                foreach(${{paramName}} as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['{{baseName}}'] = ${{paramName}};
+            }
+        {{/style}}
+        {{^style}}
             $queryParams['{{baseName}}'] = ${{paramName}};
+        {{/style}}
         }
         {{/isExplode}}
         {{^isExplode}}
@@ -487,7 +498,6 @@ use {{invokerPackage}}\ObjectSerializer;
             $queryParams['{{baseName}}'] = ${{paramName}};
         }
         {{/isExplode}}
-
         {{/queryParams}}
 
         {{#headerParams}}
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 5dacb7f31086..c2508552e1a0 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -1740,7 +1740,6 @@ protected function testBodyWithQueryParamsRequest($query, $body)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($query)) {
             $query = ObjectSerializer::serializeCollection($query, '', true);
@@ -1751,7 +1750,6 @@ protected function testBodyWithQueryParamsRequest($query, $body)
 
 
 
-
         // body params
         $_tempBody = null;
         if (isset($body)) {
@@ -2674,7 +2672,6 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($enum_query_string_array)) {
             $enum_query_string_array = ObjectSerializer::serializeCollection($enum_query_string_array, 'form', true);
@@ -2682,8 +2679,6 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
         if ($enum_query_string_array !== null) {
             $queryParams['enum_query_string_array'] = $enum_query_string_array;
         }
-
-
         // query params
         if (is_array($enum_query_string)) {
             $enum_query_string = ObjectSerializer::serializeCollection($enum_query_string, '', true);
@@ -2691,8 +2686,6 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
         if ($enum_query_string !== null) {
             $queryParams['enum_query_string'] = $enum_query_string;
         }
-
-
         // query params
         if (is_array($enum_query_integer)) {
             $enum_query_integer = ObjectSerializer::serializeCollection($enum_query_integer, '', true);
@@ -2700,8 +2693,6 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
         if ($enum_query_integer !== null) {
             $queryParams['enum_query_integer'] = $enum_query_integer;
         }
-
-
         // query params
         if (is_array($enum_query_double)) {
             $enum_query_double = ObjectSerializer::serializeCollection($enum_query_double, '', true);
@@ -2710,7 +2701,6 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
             $queryParams['enum_query_double'] = $enum_query_double;
         }
 
-
         // header params
         if (is_array($enum_header_string_array)) {
             $enum_header_string_array = ObjectSerializer::serializeCollection($enum_header_string_array, 'csv');
@@ -3001,7 +2991,6 @@ protected function testGroupParametersRequest($associative_array)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($required_string_group)) {
             $required_string_group = ObjectSerializer::serializeCollection($required_string_group, '', true);
@@ -3009,8 +2998,6 @@ protected function testGroupParametersRequest($associative_array)
         if ($required_string_group !== null) {
             $queryParams['required_string_group'] = $required_string_group;
         }
-
-
         // query params
         if (is_array($required_int64_group)) {
             $required_int64_group = ObjectSerializer::serializeCollection($required_int64_group, '', true);
@@ -3018,8 +3005,6 @@ protected function testGroupParametersRequest($associative_array)
         if ($required_int64_group !== null) {
             $queryParams['required_int64_group'] = $required_int64_group;
         }
-
-
         // query params
         if (is_array($string_group)) {
             $string_group = ObjectSerializer::serializeCollection($string_group, '', true);
@@ -3027,8 +3012,6 @@ protected function testGroupParametersRequest($associative_array)
         if ($string_group !== null) {
             $queryParams['string_group'] = $string_group;
         }
-
-
         // query params
         if (is_array($int64_group)) {
             $int64_group = ObjectSerializer::serializeCollection($int64_group, '', true);
@@ -3037,7 +3020,6 @@ protected function testGroupParametersRequest($associative_array)
             $queryParams['int64_group'] = $int64_group;
         }
 
-
         // header params
         if ($required_boolean_group !== null) {
             $headerParams['required_boolean_group'] = ObjectSerializer::toHeaderValue($required_boolean_group);
@@ -3758,7 +3740,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($pipe)) {
             $pipe = ObjectSerializer::serializeCollection($pipe, 'form', true);
@@ -3766,8 +3747,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($pipe !== null) {
             $queryParams['pipe'] = $pipe;
         }
-
-
         // query params
         if (is_array($ioutil)) {
             $ioutil = ObjectSerializer::serializeCollection($ioutil, 'csv', true);
@@ -3775,8 +3754,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($ioutil !== null) {
             $queryParams['ioutil'] = $ioutil;
         }
-
-
         // query params
         if (is_array($http)) {
             $http = ObjectSerializer::serializeCollection($http, 'spaceDelimited', true);
@@ -3784,8 +3761,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($http !== null) {
             $queryParams['http'] = $http;
         }
-
-
         // query params
         if (is_array($url)) {
             $url = ObjectSerializer::serializeCollection($url, 'form', true);
@@ -3793,16 +3768,20 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($url !== null) {
             $queryParams['url'] = $url;
         }
-
-
         // query params
         if ($context !== null) {
-            $queryParams['context'] = $context;
+            if('form' === 'form' && is_array($context)) {
+                foreach($context as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['context'] = $context;
+            }
         }
 
 
 
-
         // body params
         $_tempBody = null;
 
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 f949d0acb66c..90c6ef022319 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
@@ -775,7 +775,6 @@ protected function findPetsByStatusRequest($status)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($status)) {
             $status = ObjectSerializer::serializeCollection($status, 'form', true);
@@ -786,7 +785,6 @@ protected function findPetsByStatusRequest($status)
 
 
 
-
         // body params
         $_tempBody = null;
 
@@ -1053,7 +1051,6 @@ protected function findPetsByTagsRequest($tags)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($tags)) {
             $tags = ObjectSerializer::serializeCollection($tags, 'form', true);
@@ -1064,7 +1061,6 @@ protected function findPetsByTagsRequest($tags)
 
 
 
-
         // body params
         $_tempBody = null;
 
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 9345f4b155b5..22b217fc4eaa 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
@@ -1482,7 +1482,6 @@ protected function loginUserRequest($username, $password)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($username)) {
             $username = ObjectSerializer::serializeCollection($username, '', true);
@@ -1490,8 +1489,6 @@ protected function loginUserRequest($username, $password)
         if ($username !== null) {
             $queryParams['username'] = $username;
         }
-
-
         // query params
         if (is_array($password)) {
             $password = ObjectSerializer::serializeCollection($password, '', true);
@@ -1502,7 +1499,6 @@ protected function loginUserRequest($username, $password)
 
 
 
-
         // body params
         $_tempBody = null;
 
diff --git a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
index e2a83116f44f..6d1a24aa7de8 100644
--- a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -1774,15 +1774,20 @@ protected function testBodyWithQueryParamsRequest($query, $user)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if ($query !== null) {
-            $queryParams['query'] = $query;
+            if('form' === 'form' && is_array($query)) {
+                foreach($query as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['query'] = $query;
+            }
         }
 
 
 
-
         // body params
         $_tempBody = null;
         if (isset($user)) {
@@ -2705,31 +2710,51 @@ protected function testEnumParametersRequest($enum_header_string_array = null, $
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if ($enum_query_string_array !== null) {
-            $queryParams['enum_query_string_array'] = $enum_query_string_array;
+            if('form' === 'form' && is_array($enum_query_string_array)) {
+                foreach($enum_query_string_array as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['enum_query_string_array'] = $enum_query_string_array;
+            }
         }
-
-
         // query params
         if ($enum_query_string !== null) {
-            $queryParams['enum_query_string'] = $enum_query_string;
+            if('form' === 'form' && is_array($enum_query_string)) {
+                foreach($enum_query_string as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['enum_query_string'] = $enum_query_string;
+            }
         }
-
-
         // query params
         if ($enum_query_integer !== null) {
-            $queryParams['enum_query_integer'] = $enum_query_integer;
+            if('form' === 'form' && is_array($enum_query_integer)) {
+                foreach($enum_query_integer as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['enum_query_integer'] = $enum_query_integer;
+            }
         }
-
-
         // query params
         if ($enum_query_double !== null) {
-            $queryParams['enum_query_double'] = $enum_query_double;
+            if('form' === 'form' && is_array($enum_query_double)) {
+                foreach($enum_query_double as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['enum_query_double'] = $enum_query_double;
+            }
         }
 
-
         // header params
         if (is_array($enum_header_string_array)) {
             $enum_header_string_array = ObjectSerializer::serializeCollection($enum_header_string_array, 'csv');
@@ -3020,31 +3045,51 @@ protected function testGroupParametersRequest($associative_array)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if ($required_string_group !== null) {
-            $queryParams['required_string_group'] = $required_string_group;
+            if('form' === 'form' && is_array($required_string_group)) {
+                foreach($required_string_group as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['required_string_group'] = $required_string_group;
+            }
         }
-
-
         // query params
         if ($required_int64_group !== null) {
-            $queryParams['required_int64_group'] = $required_int64_group;
+            if('form' === 'form' && is_array($required_int64_group)) {
+                foreach($required_int64_group as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['required_int64_group'] = $required_int64_group;
+            }
         }
-
-
         // query params
         if ($string_group !== null) {
-            $queryParams['string_group'] = $string_group;
+            if('form' === 'form' && is_array($string_group)) {
+                foreach($string_group as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['string_group'] = $string_group;
+            }
         }
-
-
         // query params
         if ($int64_group !== null) {
-            $queryParams['int64_group'] = $int64_group;
+            if('form' === 'form' && is_array($int64_group)) {
+                foreach($int64_group as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['int64_group'] = $int64_group;
+            }
         }
 
-
         // header params
         if ($required_boolean_group !== null) {
             $headerParams['required_boolean_group'] = ObjectSerializer::toHeaderValue($required_boolean_group);
@@ -3769,13 +3814,17 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if ($pipe !== null) {
-            $queryParams['pipe'] = $pipe;
+            if('form' === 'form' && is_array($pipe)) {
+                foreach($pipe as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['pipe'] = $pipe;
+            }
         }
-
-
         // query params
         if (is_array($ioutil)) {
             $ioutil = ObjectSerializer::serializeCollection($ioutil, 'form', true);
@@ -3783,8 +3832,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($ioutil !== null) {
             $queryParams['ioutil'] = $ioutil;
         }
-
-
         // query params
         if (is_array($http)) {
             $http = ObjectSerializer::serializeCollection($http, 'spaceDelimited', true);
@@ -3792,8 +3839,6 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($http !== null) {
             $queryParams['http'] = $http;
         }
-
-
         // query params
         if (is_array($url)) {
             $url = ObjectSerializer::serializeCollection($url, 'form', true);
@@ -3801,16 +3846,20 @@ protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $ht
         if ($url !== null) {
             $queryParams['url'] = $url;
         }
-
-
         // query params
         if ($context !== null) {
-            $queryParams['context'] = $context;
+            if('form' === 'form' && is_array($context)) {
+                foreach($context as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['context'] = $context;
+            }
         }
 
 
 
-
         // body params
         $_tempBody = null;
 
diff --git a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
index 993e951e1bbd..4e1803989cac 100644
--- a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
+++ b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
@@ -801,7 +801,6 @@ protected function findPetsByStatusRequest($status)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($status)) {
             $status = ObjectSerializer::serializeCollection($status, 'form', true);
@@ -812,7 +811,6 @@ protected function findPetsByStatusRequest($status)
 
 
 
-
         // body params
         $_tempBody = null;
 
@@ -1079,7 +1077,6 @@ protected function findPetsByTagsRequest($tags)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if (is_array($tags)) {
             $tags = ObjectSerializer::serializeCollection($tags, 'form', true);
@@ -1090,7 +1087,6 @@ protected function findPetsByTagsRequest($tags)
 
 
 
-
         // body params
         $_tempBody = null;
 
diff --git a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
index 4da3fa6fe20b..a274723a1fb7 100644
--- a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
+++ b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
@@ -1482,21 +1482,31 @@ protected function loginUserRequest($username, $password)
         $httpBody = '';
         $multipart = false;
 
-
         // query params
         if ($username !== null) {
-            $queryParams['username'] = $username;
+            if('form' === 'form' && is_array($username)) {
+                foreach($username as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['username'] = $username;
+            }
         }
-
-
         // query params
         if ($password !== null) {
-            $queryParams['password'] = $password;
+            if('form' === 'form' && is_array($password)) {
+                foreach($password as $key => $value) {
+                    $queryParams[$key] = $value;
+                }
+            }
+            else {
+                $queryParams['password'] = $password;
+            }
         }
 
 
 
-
         // body params
         $_tempBody = null;