diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
index 93b68becc4c2..e2b3b02b4bc7 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/api.mustache
@@ -732,7 +732,7 @@ use {{invokerPackage}}\ObjectSerializer;
 
         $formData = $formDataProcessor->prepare([
         {{/-first}}
-            '{{paramName}}' => ${{paramName}},
+            '{{baseName}}' => ${{paramName}},
         {{#-last}}
         ]);
 
diff --git a/modules/openapi-generator/src/main/resources/php/libraries/psr-18/api.mustache b/modules/openapi-generator/src/main/resources/php/libraries/psr-18/api.mustache
index 47a50d446cbf..cbc048f79c88 100644
--- a/modules/openapi-generator/src/main/resources/php/libraries/psr-18/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/libraries/psr-18/api.mustache
@@ -612,7 +612,7 @@ use function sprintf;
 
         $formData = $formDataProcessor->prepare([
         {{/-first}}
-            '{{paramName}}' => ${{paramName}},
+            '{{baseName}}' => ${{paramName}},
         {{#-last}}
         ]);
 
diff --git a/samples/client/echo_api/php-nextgen-streaming/src/Api/BodyApi.php b/samples/client/echo_api/php-nextgen-streaming/src/Api/BodyApi.php
index 7c067a52dca7..8d3ad73301ba 100644
--- a/samples/client/echo_api/php-nextgen-streaming/src/Api/BodyApi.php
+++ b/samples/client/echo_api/php-nextgen-streaming/src/Api/BodyApi.php
@@ -1175,7 +1175,7 @@ public function testBodyMultipartFormdataSingleBinaryRequest(
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'my_file' => $my_file,
+            'my-file' => $my_file,
         ]);
 
         $formParams = $formDataProcessor->flatten($formData);
diff --git a/samples/client/echo_api/php-nextgen/src/Api/BodyApi.php b/samples/client/echo_api/php-nextgen/src/Api/BodyApi.php
index cebcbaddd749..6c49296bfa44 100644
--- a/samples/client/echo_api/php-nextgen/src/Api/BodyApi.php
+++ b/samples/client/echo_api/php-nextgen/src/Api/BodyApi.php
@@ -1175,7 +1175,7 @@ public function testBodyMultipartFormdataSingleBinaryRequest(
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'my_file' => $my_file,
+            'my-file' => $my_file,
         ]);
 
         $formParams = $formDataProcessor->flatten($formData);
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
index 773f9bf8dfcb..c20ea5e0852e 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/FakeApi.php
@@ -5933,7 +5933,7 @@ public function testEndpointParametersRequest(
             'byte' => $byte,
             'binary' => $binary,
             'date' => $date,
-            'date_time' => $date_time,
+            'dateTime' => $date_time,
             'password' => $password,
             'callback' => $callback,
         ]);
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/PetApi.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/PetApi.php
index 3902c7701b76..912be7151209 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/PetApi.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Api/PetApi.php
@@ -2574,7 +2574,7 @@ public function uploadFileRequest(
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'additional_metadata' => $additional_metadata,
+            'additionalMetadata' => $additional_metadata,
             'file' => $file,
         ]);
 
@@ -2896,8 +2896,8 @@ public function uploadFileWithRequiredFileRequest(
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'additional_metadata' => $additional_metadata,
-            'required_file' => $required_file,
+            'additionalMetadata' => $additional_metadata,
+            'requiredFile' => $required_file,
         ]);
 
         $formParams = $formDataProcessor->flatten($formData);
diff --git a/samples/client/petstore/php/psr-18/lib/Api/FakeApi.php b/samples/client/petstore/php/psr-18/lib/Api/FakeApi.php
index 8e57b8297f6e..eb4fc7d00462 100644
--- a/samples/client/petstore/php/psr-18/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/psr-18/lib/Api/FakeApi.php
@@ -5395,7 +5395,7 @@ public function testEndpointParametersRequest($number, $double, $pattern_without
             'byte' => $byte,
             'binary' => $binary,
             'date' => $date,
-            'date_time' => $date_time,
+            'dateTime' => $date_time,
             'password' => $password,
             'callback' => $callback,
         ]);
diff --git a/samples/client/petstore/php/psr-18/lib/Api/PetApi.php b/samples/client/petstore/php/psr-18/lib/Api/PetApi.php
index f1309ba7dfe6..8d062e94d301 100644
--- a/samples/client/petstore/php/psr-18/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/psr-18/lib/Api/PetApi.php
@@ -2130,7 +2130,7 @@ public function uploadFileRequest($pet_id, $additional_metadata = null, $file =
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'additional_metadata' => $additional_metadata,
+            'additionalMetadata' => $additional_metadata,
             'file' => $file,
         ]);
 
@@ -2417,8 +2417,8 @@ public function uploadFileWithRequiredFileRequest($pet_id, $required_file, $addi
         $formDataProcessor = new FormDataProcessor();
 
         $formData = $formDataProcessor->prepare([
-            'additional_metadata' => $additional_metadata,
-            'required_file' => $required_file,
+            'additionalMetadata' => $additional_metadata,
+            'requiredFile' => $required_file,
         ]);
 
         $formParams = $formDataProcessor->flatten($formData);
@@ -2744,7 +2744,7 @@ public function uploadImageFullFormDataRequest($pet_id, $name, $photo_urls, $id
             'id' => $id,
             'category' => $category,
             'name' => $name,
-            'photo_urls' => $photo_urls,
+            'photoUrls' => $photo_urls,
             'tags' => $tags,
             'status' => $status,
             'file' => $file,