diff --git a/book/installation.rst b/book/installation.rst
index 56552f9d602..b59bf53b929 100644
--- a/book/installation.rst
+++ b/book/installation.rst
@@ -116,7 +116,7 @@ If there are any issues, correct them now before moving on.
         rm -rf app/logs/*
 
         sudo chmod +a "www-data allow delete,write,append,file_inherit,directory_inherit" app/cache app/logs
-        sudo chmod +a "yourname allow delete,write,append,file_inherit,directory_inherit" app/cache app/logs
+        sudo chmod +a "`whoami` allow delete,write,append,file_inherit,directory_inherit" app/cache app/logs
 
     **2. Using Acl on a system that does not support chmod +a**