diff --git a/hledger-ui/Hledger/UI/UIOptions.hs b/hledger-ui/Hledger/UI/UIOptions.hs
index 79ba7a4a7..7266c371b 100644
--- a/hledger-ui/Hledger/UI/UIOptions.hs
+++ b/hledger-ui/Hledger/UI/UIOptions.hs
@@ -123,7 +123,7 @@ getHledgerUIOpts :: IO UIOpts
 --getHledgerUIOpts = processArgs uimode >>= return >>= rawOptsToUIOpts
 getHledgerUIOpts = do
   args <- getArgs >>= expandArgsAt
-  let args' = replaceNumericFlags args
+  let args' = ensureDebugFlagHasVal $ replaceNumericFlags args
   let cmdargopts = either usageError id $ process uimode args'
   rawOptsToUIOpts cmdargopts
 
diff --git a/hledger-web/Hledger/Web/WebOptions.hs b/hledger-web/Hledger/Web/WebOptions.hs
index 328984acd..a3ea1617b 100644
--- a/hledger-web/Hledger/Web/WebOptions.hs
+++ b/hledger-web/Hledger/Web/WebOptions.hs
@@ -186,7 +186,7 @@ checkWebOpts = id
 
 getHledgerWebOpts :: IO WebOpts
 getHledgerWebOpts = do
-  args <- fmap replaceNumericFlags . expandArgsAt =<< getArgs
+  args <- fmap (ensureDebugFlagHasVal . replaceNumericFlags) . expandArgsAt =<< getArgs
   rawOptsToWebOpts . either usageError id $ process webmode args
 
 data Permission
diff --git a/hledger/Hledger/Cli.hs b/hledger/Hledger/Cli.hs
index 1758ae556..1431ac8ed 100644
--- a/hledger/Hledger/Cli.hs
+++ b/hledger/Hledger/Cli.hs
@@ -112,7 +112,6 @@ import Data.Bifunctor (second)
 import Data.Function ((&))
 import Data.Functor ((<&>))
 import Data.List.Extra (nubSort)
-import Data.Char (isDigit)
 
 
 -- | The overall cmdargs mode describing hledger's command-line options and subcommands.
@@ -381,15 +380,7 @@ cmdargsParse args0 addons =
       ,show args
       ])
     id
-  where args = ensureDebugHasVal args0
-
--- Convert a valueless --debug flag to one with a value.
--- See also the --debug flag definition in CliOptions.hs.
--- This makes an equals sign unnecessary with this optional-value flag.
-ensureDebugHasVal as = case break (=="--debug") as of
-  (bs,"--debug":c:cs) | null c || not (all isDigit c) -> bs++"--debug=1":c:cs
-  (bs,["--debug"])                                    -> bs++["--debug=1"]
-  _                                                   -> as
+  where args = ensureDebugFlagHasVal args0
 
 -- | cmdargs does not allow flags (options) to appear before the subcommand name.
 -- We prefer to hide this restriction from the user, making the CLI more forgiving.
diff --git a/hledger/Hledger/Cli/CliOptions.hs b/hledger/Hledger/Cli/CliOptions.hs
index e26448722..ac7c9cf93 100644
--- a/hledger/Hledger/Cli/CliOptions.hs
+++ b/hledger/Hledger/Cli/CliOptions.hs
@@ -71,6 +71,7 @@ module Hledger.Cli.CliOptions (
   defaultWidth,
   -- widthFromOpts,
   replaceNumericFlags,
+  ensureDebugFlagHasVal,
   -- | For register:
   registerWidthsFromOpts,
 
@@ -571,6 +572,15 @@ replaceNumericFlags = map replace
     replace ('-':ds) | not (null ds) && all isDigit ds = "--depth="++ds
     replace s = s
 
+-- Convert a valueless --debug flag to one with a value.
+-- See also the --debug flag definition in CliOptions.hs.
+-- This makes an equals sign unnecessary with this optional-value flag.
+ensureDebugFlagHasVal :: [String] -> [String]
+ensureDebugFlagHasVal as = case break (=="--debug") as of
+  (bs,"--debug":c:cs) | null c || not (all isDigit c) -> bs++"--debug=1":c:cs
+  (bs,["--debug"])                                    -> bs++["--debug=1"]
+  _                                                   -> as
+
 -- | Parse raw option string values to the desired final data types.
 -- Any relative smart dates will be converted to fixed dates based on
 -- today's date. Parsing failures will raise an error.