diff --git a/api.include.php b/api.include.php
index 63e0c9e3..dff88d85 100644
--- a/api.include.php
+++ b/api.include.php
@@ -7898,9 +7898,9 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
                 $usernameFormFieldName = $this->getProperty('usernameFormField', 'username');
                 $passwordFormFieldName = $this->getProperty('passwordFormField', 'password');
                 $newPasswordFormFieldName = $this->getProperty('newPasswordFormField', 'newPassword');
-                $username = isset($body->usernameFormFieldName) ? $body->usernameFormFieldName : '';
-                $password = isset($body->passwordFormFieldName) ? $body->passwordFormFieldName : '';
-                $newPassword = isset($body->newPasswordFormFieldName) ? $body->newPasswordFormFieldName : '';
+                $username = isset($body->$usernameFormFieldName) ? $body->$usernameFormFieldName : '';
+                $password = isset($body->$passwordFormFieldName) ? $body->$passwordFormFieldName : '';
+                $newPassword = isset($body->$newPasswordFormFieldName) ? $body->$newPasswordFormFieldName : '';
                 $tableName = $this->getProperty('usersTable', 'users');
                 $table = $this->reflection->getTable($tableName);
                 $usernameColumnName = $this->getProperty('usernameColumn', 'username');
diff --git a/api.php b/api.php
index 5908092f..8fa2c20f 100644
--- a/api.php
+++ b/api.php
@@ -7898,9 +7898,9 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
                 $usernameFormFieldName = $this->getProperty('usernameFormField', 'username');
                 $passwordFormFieldName = $this->getProperty('passwordFormField', 'password');
                 $newPasswordFormFieldName = $this->getProperty('newPasswordFormField', 'newPassword');
-                $username = isset($body->usernameFormFieldName) ? $body->usernameFormFieldName : '';
-                $password = isset($body->passwordFormFieldName) ? $body->passwordFormFieldName : '';
-                $newPassword = isset($body->newPasswordFormFieldName) ? $body->newPasswordFormFieldName : '';
+                $username = isset($body->$usernameFormFieldName) ? $body->$usernameFormFieldName : '';
+                $password = isset($body->$passwordFormFieldName) ? $body->$passwordFormFieldName : '';
+                $newPassword = isset($body->$newPasswordFormFieldName) ? $body->$newPasswordFormFieldName : '';
                 $tableName = $this->getProperty('usersTable', 'users');
                 $table = $this->reflection->getTable($tableName);
                 $usernameColumnName = $this->getProperty('usernameColumn', 'username');