diff --git a/readme.md b/readme.md
index cee95cc2..d23e887f 100644
--- a/readme.md
+++ b/readme.md
@@ -178,7 +178,7 @@ new Spreadsheet(document.getElementById('xss-demo'));
 
 ## Development
 
-```sheel
+```shell
 git clone https://github.com/myliang/x-spreadsheet.git
 cd x-spreadsheet
 npm install