diff --git a/modules/openapi-generator/src/main/resources/php/api.mustache b/modules/openapi-generator/src/main/resources/php/api.mustache
index 5d7f7ae88d7..baea050cb31 100644
--- a/modules/openapi-generator/src/main/resources/php/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api.mustache
@@ -606,7 +606,7 @@ use {{invokerPackage}}\ObjectSerializer;
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 43a4ab653e7..de487424169 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
@@ -368,7 +368,7 @@ class AnotherFakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 6dc035e2188..92b7e95b2d1 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
@@ -343,7 +343,7 @@ class DefaultApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 4bbcc72ddca..e9d8eb598e9 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -351,7 +351,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -597,7 +597,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -861,7 +861,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1125,7 +1125,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1389,7 +1389,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1653,7 +1653,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1923,7 +1923,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2139,7 +2139,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2355,7 +2355,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2590,7 +2590,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2868,7 +2868,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -3280,7 +3280,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -3582,7 +3582,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -3895,7 +3895,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -4123,7 +4123,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -4360,7 +4360,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -4686,7 +4686,7 @@ class FakeApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 c76f9bca35f..faead8d187f 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
@@ -368,7 +368,7 @@ class FakeClassnameTags123Api
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 56ae41225ac..a874cf18b1c 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
@@ -334,7 +334,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -579,7 +579,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -863,7 +863,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1153,7 +1153,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1437,7 +1437,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1686,7 +1686,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1940,7 +1940,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2250,7 +2250,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2566,7 +2566,7 @@ class PetApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 8f10507e35f..b246f828202 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
@@ -316,7 +316,7 @@ class StoreApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -577,7 +577,7 @@ class StoreApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -869,7 +869,7 @@ class StoreApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1147,7 +1147,7 @@ class StoreApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
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 0ce53c64f51..54fb9239a67 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
@@ -314,7 +314,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -538,7 +538,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -762,7 +762,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -988,7 +988,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1268,7 +1268,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1567,7 +1567,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -1774,7 +1774,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }
 
@@ -2017,7 +2017,7 @@ class UserApi
 
             } else {
                 // for HTTP post (form)
-                $httpBody = ObjectSerializer::buildQuery($queryParams);
+                $httpBody = ObjectSerializer::buildQuery($formParams);
             }
         }