diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index c0d7d9597b8f569a1e996072bef667f517e74bd2..0a210e4bea49d49e9d38de402cc355ed4acc6a71 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -66,9 +66,10 @@ COMMANDS
 	to the names of remotes if trunk/branches/tags are
 	specified.  The prefix does not automatically include a
 	trailing slash, so be sure you include one in the
-	argument if that is what you want.  This is useful if
-	you wish to track multiple projects that share a common
-	repository.
+	argument if that is what you want.  If --branches/-b is
+	specified, the prefix must include a trailing slash.
+	Setting a prefix is useful if you wish to track multiple
+	projects that share a common repository.
 
 'fetch'::
 	Fetch unfetched revisions from the Subversion remote we are