diff --git a/man/gnt-backup.sgml b/man/gnt-backup.sgml
index 8d4943bf12281f47fc2c9d2ca431d58f0df3b9df..fa1c0c58129d5e7af1eb1af45df2cfadc90023dc 100644
--- a/man/gnt-backup.sgml
+++ b/man/gnt-backup.sgml
@@ -140,7 +140,8 @@
 
       <para>
         The <option>-m</option> option specifies the memory size for
-        the instance, in mebibytes (defaults to 128 MiB).
+        the instance, in mebibytes (defaults to 128 MiB). Again, you
+        can use other suffixes (e.g. <userinput>2g</userinput>).
       </para>
 
       <para>