diff --git a/README.md b/README.md
index 80a3f96..4007c4d 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ from markdown_generator.mdconverter_class import MultiNdconverter
 file_list = ['04-Model\\06-GoogleGenerativeAI.ipynb'] # 리스트 형식으로 파일 경로
 app = MultiNdconverter(filenames=file_list)
 app.css_filename = "../css/styles.css" # css 파일 설정
-app.post_fix = "-(CEHCK)" # option
+app.post_fix = "-(CHECK)" # option
 app.run()
 ```
 
diff --git a/sample/test.ipynb b/sample/test.ipynb
index 5ca987d..139abed 100644
--- a/sample/test.ipynb
+++ b/sample/test.ipynb
@@ -59,6 +59,7 @@
     "\n",
     "app = MultiNdconverter(filenames=file_list)\n",
     "app.css_filename = \"../css/styles.css\"\n",
+    "app.post_fix = \"-(CHECK)\" # option\n",
     "app.run()"
    ]
   }