diff --git a/bin/hledger-check-dupes.hs b/bin/hledger-check-dupes.hs
deleted file mode 100755
index 26166a82b..000000000
--- a/bin/hledger-check-dupes.hs
+++ /dev/null
@@ -1,59 +0,0 @@
-#!/usr/bin/env stack
-{- stack runghc --verbosity info
-   --package hledger-lib
-   --package hledger
-   --package here
-   --package text
--}
-
-{-# OPTIONS_GHC -Wno-missing-signatures -Wno-name-shadowing #-}
-{-# LANGUAGE QuasiQuotes #-}
-
-import Hledger
-import Hledger.Cli
-import Text.Printf (printf)
--- import System.Environment (getArgs)
-import Data.List
-import Data.Function
-import Data.String.Here
-import qualified Data.Text as T
-
-------------------------------------------------------------------------------
-cmdmode = hledgerCommandMode
-  [here| check-dupes
-Reports duplicates in the account tree: account names having the same leaf
-but different prefixes. In other words, two or more leaves that are
-categorized differently.
-Reads the default journal file, or another specified as an argument.
- 
-http://stefanorodighiero.net/software/hledger-dupes.html
-  |]
-  []
-  [generalflagsgroup1]
-  []
-  ([], Nothing)
-------------------------------------------------------------------------------
-
-main = do
-  opts <- getHledgerCliOpts cmdmode
-  withJournalDo opts $ \CliOpts{rawopts_=_opts,reportopts_=_ropts} j -> do
-    mapM_ render $ checkdupes $ accountsNames j
-
-accountsNames :: Journal -> [(String, AccountName)]
-accountsNames j = map leafAndAccountName as
-  where leafAndAccountName a = (T.unpack $ accountLeafName a, a)
-        ps = journalPostings j
-        as = nub $ sort $ map paccount ps
-
-
-checkdupes :: (Ord k, Eq k) => [(k, v)] -> [(k, [v])]
-checkdupes l = zip dupLeafs dupAccountNames
-  where dupLeafs = map (fst . head) d
-        dupAccountNames = map (map snd) d
-        d = dupes' l
-        dupes' = filter ((> 1) . length)
-          . groupBy ((==) `on` fst)
-          . sortBy (compare `on` fst)
-
-render :: (String, [AccountName]) -> IO ()
-render (leafName, accountNameL) = printf "%s as %s\n" leafName (concat $ intersperse ", " (map T.unpack accountNameL))
diff --git a/hledger/Hledger/Cli/Commands.hs b/hledger/Hledger/Cli/Commands.hs
index 3274655ae..f7e27ce30 100644
--- a/hledger/Hledger/Cli/Commands.hs
+++ b/hledger/Hledger/Cli/Commands.hs
@@ -19,6 +19,7 @@ module Hledger.Cli.Commands (
   ,module Hledger.Cli.Commands.Balancesheetequity
   ,module Hledger.Cli.Commands.Cashflow
   ,module Hledger.Cli.Commands.Checkdates
+  ,module Hledger.Cli.Commands.Checkdupes
   ,module Hledger.Cli.Commands.Help
   ,module Hledger.Cli.Commands.Incomestatement
   ,module Hledger.Cli.Commands.Print
@@ -49,6 +50,7 @@ import Hledger.Cli.Commands.Balancesheet
 import Hledger.Cli.Commands.Balancesheetequity
 import Hledger.Cli.Commands.Cashflow
 import Hledger.Cli.Commands.Checkdates
+import Hledger.Cli.Commands.Checkdupes
 import Hledger.Cli.Commands.Help
 import Hledger.Cli.Commands.Incomestatement
 import Hledger.Cli.Commands.Print
diff --git a/hledger/Hledger/Cli/Commands/Checkdupes.hs b/hledger/Hledger/Cli/Commands/Checkdupes.hs
new file mode 100755
index 000000000..d9b0c1199
--- /dev/null
+++ b/hledger/Hledger/Cli/Commands/Checkdupes.hs
@@ -0,0 +1,49 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Hledger.Cli.Commands.Checkdupes (
+  checkdupesmode
+ ,checkdupes
+) 
+where
+
+import Data.Function
+import Data.List
+import Data.String.Here
+import qualified Data.Text as T
+import Hledger
+import Hledger.Cli.CliOptions
+import System.Console.CmdArgs.Explicit
+import Text.Printf
+
+checkdupesmode :: Mode RawOpts
+checkdupesmode = hledgerCommandMode
+  [here| check-dupes
+Reports account names having the same leaf but different prefixes. 
+In other words, two or more leaves that are categorized differently.
+Reads the default journal file, or another specified as an argument.
+An example: http://stefanorodighiero.net/software/hledger-dupes.html
+  |]
+  []
+  [generalflagsgroup1]
+  []
+  ([], Nothing)
+
+checkdupes _opts j = mapM_ render $ checkdupes' $ accountsNames j
+
+accountsNames :: Journal -> [(String, AccountName)]
+accountsNames j = map leafAndAccountName as
+  where leafAndAccountName a = (T.unpack $ accountLeafName a, a)
+        ps = journalPostings j
+        as = nub $ sort $ map paccount ps
+
+checkdupes' :: (Ord k, Eq k) => [(k, v)] -> [(k, [v])]
+checkdupes' l = zip dupLeafs dupAccountNames
+  where dupLeafs = map (fst . head) d
+        dupAccountNames = map (map snd) d
+        d = dupes' l
+        dupes' = filter ((> 1) . length)
+          . groupBy ((==) `on` fst)
+          . sortBy (compare `on` fst)
+
+render :: (String, [AccountName]) -> IO ()
+render (leafName, accountNameL) = printf "%s as %s\n" leafName (concat $ intersperse ", " (map T.unpack accountNameL))
diff --git a/hledger/doc/addons.m4.md b/hledger/doc/addons.m4.md
index 02e3ccc0f..c8287759a 100644
--- a/hledger/doc/addons.m4.md
+++ b/hledger/doc/addons.m4.md
@@ -89,11 +89,6 @@ is an old pie chart generator, in need of some love.
 [hledger-check.hs](https://github.com/simonmichael/hledger/blob/master/bin/hledger-check.hs)
 checks more powerful account balance assertions.
 
-### check-dupes
-
-[hledger-check-dupes.hs](https://github.com/simonmichael/hledger/blob/master/bin/hledger-check-dupes.hs#L21)
-checks for account names sharing the same leaf name.
-
 ### equity
 
 [hledger-equity.hs](https://github.com/simonmichael/hledger/blob/master/bin/hledger-equity.hs#L17)
diff --git a/hledger/doc/commands.m4.md b/hledger/doc/commands.m4.md
index 13725d0cd..1ac95e258 100644
--- a/hledger/doc/commands.m4.md
+++ b/hledger/doc/commands.m4.md
@@ -345,6 +345,10 @@ you can alter the report mode with `--change`/`--cumulative`/`--historical`.
 Check that transactions are sorted by increasing date.
 With a query, only matched transactions' dates are checked.
 
+## check-dupes
+Reports account names having the same leaf but different prefixes. 
+An example: http://stefanorodighiero.net/software/hledger-dupes.html
+
 ## help
 Show any of the hledger manuals.
 
diff --git a/hledger/hledger.cabal b/hledger/hledger.cabal
index 455e85d0b..e41ac60fb 100644
--- a/hledger/hledger.cabal
+++ b/hledger/hledger.cabal
@@ -130,6 +130,7 @@ library
       Hledger.Cli.Commands.Balancesheetequity
       Hledger.Cli.Commands.Cashflow
       Hledger.Cli.Commands.Checkdates
+      Hledger.Cli.Commands.Checkdupes
       Hledger.Cli.Commands.Help
       Hledger.Cli.Commands.Incomestatement
       Hledger.Cli.Commands.Print
diff --git a/hledger/package.yaml b/hledger/package.yaml
index 4c3e585bd..27b843416 100644
--- a/hledger/package.yaml
+++ b/hledger/package.yaml
@@ -111,6 +111,7 @@ library:
   - Hledger.Cli.Commands.Balancesheetequity
   - Hledger.Cli.Commands.Cashflow
   - Hledger.Cli.Commands.Checkdates
+  - Hledger.Cli.Commands.Checkdupes
   - Hledger.Cli.Commands.Help
   - Hledger.Cli.Commands.Incomestatement
   - Hledger.Cli.Commands.Print