diff --git a/plugins/baser-core/src/Service/ThemesService.php b/plugins/baser-core/src/Service/ThemesService.php
index e60a5eaeb8..734e123179 100644
--- a/plugins/baser-core/src/Service/ThemesService.php
+++ b/plugins/baser-core/src/Service/ThemesService.php
@@ -32,6 +32,7 @@
 use Cake\Routing\Router;
 use Cake\Utility\Inflector;
 use Laminas\Diactoros\UploadedFile;
+use BaserCore\Utility\BcFile;
 
 /**
  * ThemesService
@@ -362,6 +363,47 @@ public function loadDefaultDataPattern(string $currentTheme, string $dbDataPatte
         return $result;
     }
 
+    /**
+     * ヘルパーのnamespaceを変更する
+     */
+    public function changeHelperNameSpace($newTheme)
+    {
+        $pluginPath = BcUtil::getPluginPath($newTheme);
+        if (!$pluginPath) return false;
+        if (file_exists($pluginPath . 'src' . DS .'View' . DS .'Helper'. DS . $newTheme. 'Helper.php')) {
+            $helperClassPath = $pluginPath . 'src' . DS .'View' . DS .'Helper'. DS . $newTheme. 'Helper.php';
+         }else{
+            return false;
+         }
+         $file = new BcFile($helperClassPath);
+         $data = $file->read();
+         $file->write(preg_replace('/namespace .+?;/', 'namespace ' . $newTheme . '\View\Helper;', $data));
+         return true;
+    }
+
+    /**
+     * ヘルパーのクラス名を変更する
+     */
+    public function ChangeHelperClassName($oldTheme,$newTheme)
+    {
+        $pluginPath = BcUtil::getPluginPath($newTheme);
+        if (!$pluginPath) return false;
+        $oldPath = $pluginPath . 'src'. DS .'View' . DS .'Helper' . DS . $oldTheme . 'Helper.php';
+        $newPath = $pluginPath . 'src'. DS .'View' . DS .'Helper' . DS . $newTheme . 'Helper.php';
+        if(!file_exists($newPath))
+        {
+            if(file_exists($oldPath)) {
+                rename($oldPath, $newPath);
+            } else {
+                return false;
+            }
+        }
+        $file = new BcFile($newPath);
+        $data = $file->read();
+        $file->write(preg_replace('/class\s+.*?Helper/', 'class ' . $newTheme . 'Helper', $data));
+        return true;
+    }
+
     /**
      * コピーする
      *
@@ -399,6 +441,8 @@ public function copy(string $theme): bool
         }
         BcUtil::changePluginClassName($oldTheme, $newTheme);
         BcUtil::changePluginNameSpace($newTheme);
+        $this->ChangeHelperClassName($oldTheme,$newTheme);
+        $this->changeHelperNameSpace($newTheme);
         return true;
     }