diff --git a/cmd/check/check.go b/cmd/check/check.go
index 6337f6834..8251d8e47 100644
--- a/cmd/check/check.go
+++ b/cmd/check/check.go
@@ -72,6 +72,9 @@ you what happened to it. These are reminiscent of diff files.
 - |+ path| means path was missing on the destination, so only in the source
 - |* path| means path was present in source and destination but different.
 - |! path| means there was an error reading or hashing the source or dest.
+
+The default number of parallel checks is 8. See the [--checkers=N](/docs/#checkers-n)
+option for more information.
 `, "|", "`")
 
 // GetCheckOpt gets the options corresponding to the check flags