diff --git a/doc/boot_arguments.md b/doc/boot_arguments.md
index 451ff0f24b..960e978e42 100644
--- a/doc/boot_arguments.md
+++ b/doc/boot_arguments.md
@@ -30,7 +30,7 @@ Changing complex options (e.g., collections) is not supported yet.
 ## Proxy Setup
 
 Agama supports proxy setup using the `proxy=` kernel command line option like 
-`proxy=http://192.168.122.1:3128` when the installation requires to use an HTTP, HTTPS os FTPS
+`proxy=http://192.168.122.1:3128` when the installation requires to use an HTTP, HTTPS or FTP
 source . The supported proxy URL format is: protocol://[user[:password]@]host[:port]
 
 When the installation system boots, the agama-proxy-setup service will read the proxy url to be