diff --git a/doc/040_backup.rst b/doc/040_backup.rst
index b98961cc7..dbc65b51d 100644
--- a/doc/040_backup.rst
+++ b/doc/040_backup.rst
@@ -346,12 +346,12 @@ option:
 
     $ restic -r /srv/restic-repo backup ~/work --exclude-larger-than 1M
 
-This excludes files in ``~/work`` which are larger than 1 MB from the backup.
+This excludes files in ``~/work`` which are larger than 1 MiB from the backup.
 
 The default unit for the size value is bytes, so e.g. ``--exclude-larger-than 2048``
-would exclude files larger than 2048 bytes (2 kilobytes). To specify other units,
-suffix the size value with one of ``k``/``K`` for kilobytes, ``m``/``M`` for megabytes,
-``g``/``G`` for gigabytes and ``t``/``T`` for terabytes (e.g. ``1k``, ``10K``, ``20m``,
+would exclude files larger than 2048 bytes (2 KiB). To specify other units,
+suffix the size value with one of ``k``/``K`` for KiB (1024 bytes), ``m``/``M`` for MiB (1024^2 bytes),
+``g``/``G`` for GiB (1024^3 bytes) and ``t``/``T`` for TiB (1024^4 bytes), e.g. ``1k``, ``10K``, ``20m``,
 ``20M``,  ``30g``, ``30G``, ``2t`` or ``2T``).
 
 Including Files