diff --git a/doc/common.m4 b/doc/common.m4
index ea546ca6c..2f9eb48aa 100644
--- a/doc/common.m4
+++ b/doc/common.m4
@@ -173,8 +173,8 @@ m4_define({{_reportingoptions_}}, {{
 : apply [automated posting rules](journal.html#auto-postings-transaction-modifiers) to modify transactions.
 
 `--forecast`
-: apply [periodic transaction](journal.html#periodic-transactions) rules to generate future transactions, to 6 months from now or report end date.
-
+: generate future transactions from [periodic transaction](journal.html#periodic-transactions) rules, for the next 6 months or till report end date.
+In hledger-ui, also make ordinary future transactions visible.
 
 When a reporting option appears more than once in the command line, the last one takes precedence.
 
diff --git a/hledger/Hledger/Cli/CliOptions.hs b/hledger/Hledger/Cli/CliOptions.hs
index 6e71c2dc4..67a4ce486 100644
--- a/hledger/Hledger/Cli/CliOptions.hs
+++ b/hledger/Hledger/Cli/CliOptions.hs
@@ -179,7 +179,7 @@ reportflags = [
 
   -- generated postings/transactions
  ,flagNone ["auto"]          (setboolopt "auto") "apply automated posting rules to modify transactions"
- ,flagNone ["forecast"]      (setboolopt "forecast") "apply periodic transaction rules to generate future transactions, to 6 months from now or report end date"
+ ,flagNone ["forecast"]      (setboolopt "forecast") "generate future transactions from periodic transaction rules, for the next 6 months or till report end date. In hledger-ui, also make ordinary future transactions visible."
 
  ]