diff --git a/src/nix/profile-wipe-history.md b/src/nix/profile-wipe-history.md
index b4b26286463..ece2d1286de 100644
--- a/src/nix/profile-wipe-history.md
+++ b/src/nix/profile-wipe-history.md
@@ -15,6 +15,8 @@ R""(
 This command deletes non-current versions of a profile, making it
 impossible to roll back to these versions. By default, all non-current
 versions are deleted. With `--older-than` *N*`d`, all non-current
-versions older than *N* days are deleted.
+versions older than *N* days are deleted. With `--older-than` `+`*N*,
+*N* older versions than the current version will be kept, the rest
+removed.
 
 )""
diff --git a/src/nix/profile.cc b/src/nix/profile.cc
index dd1a1dff37e..901ee50469a 100644
--- a/src/nix/profile.cc
+++ b/src/nix/profile.cc
@@ -832,8 +832,8 @@ struct CmdProfileWipeHistory : virtual StoreCommand, MixDefaultProfile, MixDryRu
             .longName = "older-than",
             .description =
                 "Delete versions older than the specified age. *age* "
-                "must be in the format *N*`d`, where *N* denotes a number "
-                "of days.",
+                "must be in the format *N*`d` or `+`*N* where *N* denotes a number. "
+                "Use `d` for days and `+` for absolute number to keep.",
             .labels = {"age"},
             .handler = {&minAge},
         });