diff --git a/doc/guix.texi b/doc/guix.texi
index adb1975935..817b336654 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -17454,6 +17454,17 @@ $ sudo filefrag -e /swapfile | grep '^ *0:' | cut -d: -f3 | cut -d. -f1
    92514304
 @end smallexample
 
+Note that if @file{/swapfile} lives on an encrypted root file system,
+you will instead need to specify the mapped device as the @code{resume}
+argument, like so:
+
+@lisp
+(kernel-arguments
+  (cons* "resume=/dev/mapper/cryptroot"  ;device holding /swapfile
+         "resume_offset=92514304"
+         %default-kernel-arguments))
+@end lisp
+
 @node User Accounts
 @section User Accounts