diff --git a/src/main/resources/php/Swagger.mustache b/src/main/resources/php/Swagger.mustache
index 962cc53455f..a176b68aa0d 100644
--- a/src/main/resources/php/Swagger.mustache
+++ b/src/main/resources/php/Swagger.mustache
@@ -77,7 +77,8 @@ class APIClient {
 		    $headers[] = "api_key: " . $this->apiKey;
 		}
 
-		if (is_object($postData) or is_array($postData)) {
+
+		if (strpos($headers['Content-Type'], "multipart/form-data") < 0 and (is_object($postData) or is_array($postData))) {
 			$postData = json_encode($this->sanitizeForSerialization($postData));
 		}
 
diff --git a/src/main/resources/php/api.mustache b/src/main/resources/php/api.mustache
index 30d34f556e7..43ffbaa60a5 100644
--- a/src/main/resources/php/api.mustache
+++ b/src/main/resources/php/api.mustache
@@ -72,7 +72,12 @@ class {{classname}} {
       }
       {{#formParams}}
       if(${{paramName}} != null) {
+        {{#notFile}}
         $body['{{paramName}}'] = ${{paramName}};
+        {{/notFile}}
+        {{#isFile}}
+        $body['{{paramName}}'] = '@' . ${{paramName}};
+        {{/isFile}}
       }
       {{/formParams}}
       if (empty($body)) {