diff --git a/hledger/Hledger/Cli/Commands.hs b/hledger/Hledger/Cli/Commands.hs
index ce209e8c0..3274655ae 100644
--- a/hledger/Hledger/Cli/Commands.hs
+++ b/hledger/Hledger/Cli/Commands.hs
@@ -18,6 +18,7 @@ module Hledger.Cli.Commands (
   ,module Hledger.Cli.Commands.Balancesheet
   ,module Hledger.Cli.Commands.Balancesheetequity
   ,module Hledger.Cli.Commands.Cashflow
+  ,module Hledger.Cli.Commands.Checkdates
   ,module Hledger.Cli.Commands.Help
   ,module Hledger.Cli.Commands.Incomestatement
   ,module Hledger.Cli.Commands.Print
@@ -47,6 +48,7 @@ import Hledger.Cli.Commands.Balance
 import Hledger.Cli.Commands.Balancesheet
 import Hledger.Cli.Commands.Balancesheetequity
 import Hledger.Cli.Commands.Cashflow
+import Hledger.Cli.Commands.Checkdates
 import Hledger.Cli.Commands.Help
 import Hledger.Cli.Commands.Incomestatement
 import Hledger.Cli.Commands.Print
@@ -65,6 +67,7 @@ builtinCommands = [
   ,(balancesheetmode       , balancesheet) 
   ,(balancesheetequitymode , balancesheetequity) 
   ,(cashflowmode           , cashflow) 
+  ,(checkdatesmode         , checkdates) 
   ,(helpmode               , help') 
   ,(incomestatementmode    , incomestatement) 
   ,(printmode              , print') 
diff --git a/bin/hledger-check-dates.hs b/hledger/Hledger/Cli/Commands/Checkdates.hs
similarity index 50%
rename from bin/hledger-check-dates.hs
rename to hledger/Hledger/Cli/Commands/Checkdates.hs
index 3d01f25bc..81ebd96e0 100755
--- a/bin/hledger-check-dates.hs
+++ b/hledger/Hledger/Cli/Commands/Checkdates.hs
@@ -5,16 +5,23 @@
    --package here
 -}
 
-{-# OPTIONS_GHC -Wno-missing-signatures -Wno-name-shadowing #-}
 {-# LANGUAGE QuasiQuotes #-}
 
+module Hledger.Cli.Commands.Checkdates (
+  checkdatesmode
+ ,checkdates
+ ,tests_Hledger_Cli_Commands_Checkdates
+) where
+
 import Data.String.Here
 import Hledger
-import Hledger.Cli
+import Hledger.Cli.CliOptions
+import System.Console.CmdArgs.Explicit
+import Test.HUnit
 import Text.Printf
 
-------------------------------------------------------------------------------
-cmdmode = hledgerCommandMode
+-- checkdatesmode :: Mode RawOpts
+checkdatesmode = hledgerCommandMode
   [here| check-dates
 Check that transactions' dates are monotonically increasing.
 With --date2, checks secondary dates instead.
@@ -27,38 +34,34 @@ FLAGS
   [generalflagsgroup1]
   []
   ([], Just $ argsFlag "[QUERY]")
-------------------------------------------------------------------------------
 
-main :: IO ()
-main = do
-  opts <- getHledgerCliOpts cmdmode
-  withJournalDo opts $
-   \CliOpts{rawopts_=rawopts,reportopts_=ropts} j -> do
-    d <- getCurrentDay
-    let ropts_ = ropts{accountlistmode_=ALFlat}
-    let q = queryFromOpts d ropts_
-    let ts = filter (q `matchesTransaction`) $
-             jtxns $ journalSelectingAmountFromOpts ropts j
-    let strict = boolopt "strict" rawopts
-    let date = transactionDateFn ropts
-    let compare a b =
-          if strict
-          then date a <  date b
-          else date a <= date b
-    case checkTransactions compare ts of
-     FoldAcc{fa_previous=Nothing} -> putStrLn "ok (empty journal)"
-     FoldAcc{fa_error=Nothing}    -> putStrLn "ok"
-     FoldAcc{fa_error=Just error, fa_previous=Just previous} ->
-      putStrLn $ printf ("ERROR: transaction out of%s date order"
-       ++ "\nPrevious date: %s"
-       ++ "\nDate: %s"
-       ++ "\nLocation: %s"
-       ++ "\nTransaction:\n\n%s")
-       (if strict then " STRICT" else "")
-       (show $ date previous)
-       (show $ date error)
-       (show $ tsourcepos error)
-       (showTransactionUnelided error)
+checkdates :: CliOpts -> Journal -> IO ()
+checkdates CliOpts{rawopts_=rawopts,reportopts_=ropts} j = do
+  d <- getCurrentDay
+  let ropts_ = ropts{accountlistmode_=ALFlat}
+  let q = queryFromOpts d ropts_
+  let ts = filter (q `matchesTransaction`) $
+           jtxns $ journalSelectingAmountFromOpts ropts j
+  let strict = boolopt "strict" rawopts
+  let date = transactionDateFn ropts
+  let compare a b =
+        if strict
+        then date a <  date b
+        else date a <= date b
+  case checkTransactions compare ts of
+   FoldAcc{fa_previous=Nothing} -> putStrLn "ok (empty journal)"
+   FoldAcc{fa_error=Nothing}    -> putStrLn "ok"
+   FoldAcc{fa_error=Just error, fa_previous=Just previous} ->
+    putStrLn $ printf ("ERROR: transaction out of%s date order"
+     ++ "\nPrevious date: %s"
+     ++ "\nDate: %s"
+     ++ "\nLocation: %s"
+     ++ "\nTransaction:\n\n%s")
+     (if strict then " STRICT" else "")
+     (show $ date previous)
+     (show $ date error)
+     (show $ tsourcepos error)
+     (showTransactionUnelided error)
 
 data FoldAcc a b = FoldAcc
  { fa_error    :: Maybe a
@@ -83,3 +86,7 @@ checkTransactions compare ts =
       then acc{fa_previous=Just current}
       else acc{fa_error=Just current}
 
+tests_Hledger_Cli_Commands_Checkdates :: Test
+tests_Hledger_Cli_Commands_Checkdates = TestList
+ [
+ ]
diff --git a/hledger/hledger.cabal b/hledger/hledger.cabal
index 80a53d840..455e85d0b 100644
--- a/hledger/hledger.cabal
+++ b/hledger/hledger.cabal
@@ -129,6 +129,7 @@ library
       Hledger.Cli.Commands.Balancesheet
       Hledger.Cli.Commands.Balancesheetequity
       Hledger.Cli.Commands.Cashflow
+      Hledger.Cli.Commands.Checkdates
       Hledger.Cli.Commands.Help
       Hledger.Cli.Commands.Incomestatement
       Hledger.Cli.Commands.Print
diff --git a/hledger/package.yaml b/hledger/package.yaml
index c2d88d6e6..4c3e585bd 100644
--- a/hledger/package.yaml
+++ b/hledger/package.yaml
@@ -110,6 +110,7 @@ library:
   - Hledger.Cli.Commands.Balancesheet
   - Hledger.Cli.Commands.Balancesheetequity
   - Hledger.Cli.Commands.Cashflow
+  - Hledger.Cli.Commands.Checkdates
   - Hledger.Cli.Commands.Help
   - Hledger.Cli.Commands.Incomestatement
   - Hledger.Cli.Commands.Print