diff --git a/documentation/content/en/books/handbook/cutting-edge/_index.adoc b/documentation/content/en/books/handbook/cutting-edge/_index.adoc
--- a/documentation/content/en/books/handbook/cutting-edge/_index.adoc
+++ b/documentation/content/en/books/handbook/cutting-edge/_index.adoc
@@ -1030,6 +1030,13 @@
 If a file must be manually merged, an interactive display allows the user to choose which portions of the files are kept.
 See man:mergemaster[8] for more information.
 
+If the standard [.filename]#/usr/src# was not used, another parameter must be passed to man:mergemaster[8]:
+
+[source,shell]
+....
+# mergemaster -Ui PATH_TO_SRC
+....
+
 [[updating-src-completing-check-old]]
 ==== Checking for Outdated Files and Libraries