diff --git a/documentation/ref-manual/introduction.xml b/documentation/ref-manual/introduction.xml
index b6b98598dc..40b4e21627 100644
--- a/documentation/ref-manual/introduction.xml
+++ b/documentation/ref-manual/introduction.xml
@@ -416,7 +416,7 @@
                         Source the tools environment setup script by using a
                         command like the following:
                         <literallayout class='monospaced'>
-     $ source /home/<replaceable>your-username</replaceable>/buildtools/environment-setup-i586-poky-linux
+     $ source /home/<replaceable>your_username</replaceable>/buildtools/environment-setup-i586-poky-linux
                         </literallayout>
                         Of course, you need to supply your installation directory and be
                         sure to use the right file (i.e. i585 or x86-64).