diff --git a/Coding-style-guide.md b/Coding-style-guide.md
index 45ea5c1..236928a 100644
--- a/Coding-style-guide.md
+++ b/Coding-style-guide.md
@@ -19,7 +19,7 @@ Braces should be on the same line as the function name:
 
 Private or utility functions should be prefixed with an underscore:
 
-    function _helper_util() {
+    function _helper-util() {
       ...
     }