diff --git a/hledger-lib/Hledger/Data/Dates.hs b/hledger-lib/Hledger/Data/Dates.hs
index 271a1d843..a60d11aa4 100644
--- a/hledger-lib/Hledger/Data/Dates.hs
+++ b/hledger-lib/Hledger/Data/Dates.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE NoMonoLocalBinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -93,12 +92,7 @@ import Data.Maybe
 import qualified Data.Set as Set
 import Data.Text (Text)
 import qualified Data.Text as T
-#if MIN_VERSION_time(1,5,0)
 import Data.Time.Format hiding (months)
-#else
-import Data.Time.Format
-import System.Locale (TimeLocale, defaultTimeLocale)
-#endif
 import Data.Time.Calendar
 import Data.Time.Calendar.OrdinalDate
 import Data.Time.Clock
@@ -669,23 +663,20 @@ advancetonthweekday n wd s =
 --     parseTime defaultTimeLocale "%Y-%m-%d %H:%M:%S" s
 --     ]
 
-parsetime :: ParseTime t => TimeLocale -> String -> String -> Maybe t
-parsetime =
-#if MIN_VERSION_time(1,5,0)
-     parseTimeM True
-#else
-     parseTime
-#endif
-
-
 -- | Try to parse a couple of date string formats:
 -- `YYYY-MM-DD`, `YYYY/MM/DD` or `YYYY.MM.DD`, with leading zeros required.
 -- For internal use, not quite the same as the journal's "simple dates".
+-- >>> parsedateM "2008/02/03"
+-- Just 2008-02-03
+-- >>> parsedateM "2008/02/03/"
+-- Nothing
+-- >>> parsedateM "2008/02/30"
+-- Nothing
 parsedateM :: String -> Maybe Day
 parsedateM s = asum [
-     parsetime defaultTimeLocale "%Y-%m-%d" s,
-     parsetime defaultTimeLocale "%Y/%m/%d" s,
-     parsetime defaultTimeLocale "%Y.%m.%d" s
+     parseTimeM True defaultTimeLocale "%Y-%m-%d" s,
+     parseTimeM True defaultTimeLocale "%Y/%m/%d" s,
+     parseTimeM True defaultTimeLocale "%Y.%m.%d" s
      ]
 
 
@@ -695,28 +686,9 @@ parsedateM s = asum [
 --                             (parsedatetimeM s)
 
 -- | Like parsedateM, raising an error on parse failure.
---
--- >>> parsedate "2008/02/03"
--- 2008-02-03
 parsedate :: String -> Day
-parsedate s =  fromMaybe (error' $ "could not parse date \"" ++ s ++ "\"")  -- PARTIAL:
-                         (parsedateM s)
--- doctests I haven't been able to make compatible with both GHC 7 and 8
--- -- >>> parsedate "2008/02/03/"
--- -- *** Exception: could not parse date "2008/02/03/"
--- #if MIN_VERSION_base(4,9,0)
--- -- ...
--- #endif
--- #if MIN_VERSION_time(1,6,0)
--- -- >>> parsedate "2008/02/30"  -- with time >= 1.6, invalid dates are rejected
--- -- *** Exception: could not parse date "2008/02/30"
--- #if MIN_VERSION_base(4,9,0)
--- -- ...
--- #endif
--- #else
--- -- >>> parsedate "2008/02/30"  -- with time < 1.6, they are silently adjusted
--- -- 2008-02-29
--- #endif
+parsedate s = fromMaybe (error' $ "could not parse date \"" ++ s ++ "\"")  -- PARTIAL:
+            $ parsedateM s
 
 {-|
 Parse a date in any of the formats allowed in Ledger's period expressions, and some others.
diff --git a/hledger-lib/Hledger/Data/Timeclock.hs b/hledger-lib/Hledger/Data/Timeclock.hs
index 78ea2dd54..1cf164397 100644
--- a/hledger-lib/Hledger/Data/Timeclock.hs
+++ b/hledger-lib/Hledger/Data/Timeclock.hs
@@ -6,7 +6,7 @@ converted to 'Transactions' and queried like a ledger.
 
 -}
 
-{-# LANGUAGE CPP, OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings #-}
 
 module Hledger.Data.Timeclock (
    timeclockEntriesToTransactions
@@ -21,9 +21,6 @@ import Data.Time.Calendar
 import Data.Time.Clock
 import Data.Time.Format
 import Data.Time.LocalTime
-#if !(MIN_VERSION_time(1,5,0))
-import System.Locale (defaultTimeLocale)
-#endif
 import Text.Printf
 
 import Hledger.Utils
@@ -136,11 +133,7 @@ tests_Timeclock = tests "Timeclock" [
           yesterday = prevday today
           clockin = TimeclockEntry nullsourcepos In
           mktime d = LocalTime d . fromMaybe midnight .
-#if MIN_VERSION_time(1,5,0)
                      parseTimeM True defaultTimeLocale "%H:%M:%S"
-#else
-                     parseTime defaultTimeLocale "%H:%M:%S"
-#endif
           showtime = formatTime defaultTimeLocale "%H:%M"
           txndescs = map (T.unpack . tdescription) . timeclockEntriesToTransactions now
           future = utcToLocalTime tz $ addUTCTime 100 now'
diff --git a/hledger-lib/Hledger/Read/CsvReader.hs b/hledger-lib/Hledger/Read/CsvReader.hs
index c603e1213..4c8f91d02 100644
--- a/hledger-lib/Hledger/Read/CsvReader.hs
+++ b/hledger-lib/Hledger/Read/CsvReader.hs
@@ -11,7 +11,6 @@ A reader for CSV data, using an extra rules file to help interpret the data.
 -- stack haddock hledger-lib --fast --no-haddock-deps --haddock-arguments='--ignore-all-exports' --open
 
 --- ** language
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE MultiWayIf #-}
@@ -61,12 +60,7 @@ import qualified Data.Text as T
 import qualified Data.Text.Encoding as T
 import qualified Data.Text.IO as T
 import Data.Time.Calendar (Day)
-#if MIN_VERSION_time(1,5,0)
 import Data.Time.Format (parseTimeM, defaultTimeLocale)
-#else
-import Data.Time.Format (parseTime)
-import System.Locale (defaultTimeLocale)
-#endif
 import Safe
 import System.Directory (doesFileExist)
 import System.FilePath
@@ -1229,13 +1223,7 @@ csvFieldValue rules record fieldname = do
 parseDateWithCustomOrDefaultFormats :: Maybe DateFormat -> String -> Maybe Day
 parseDateWithCustomOrDefaultFormats mformat s = asum $ map parsewith formats
   where
-    parsetime =
-#if MIN_VERSION_time(1,5,0)
-     parseTimeM True
-#else
-     parseTime
-#endif
-    parsewith = flip (parsetime defaultTimeLocale) s
+    parsewith = flip (parseTimeM True defaultTimeLocale) s
     formats = maybe
                ["%Y/%-m/%-d"
                ,"%Y-%-m-%-d"
diff --git a/hledger-ui/Hledger/UI/Main.hs b/hledger-ui/Hledger/UI/Main.hs
index 25fe32bb3..b51d4fa88 100644
--- a/hledger-ui/Hledger/UI/Main.hs
+++ b/hledger-ui/Hledger/UI/Main.hs
@@ -33,11 +33,7 @@ import System.FilePath
 import System.FSNotify
 import Brick
 
-#if MIN_VERSION_brick(0,16,0)
 import qualified Brick.BChan as BC
-#else
-import Control.Concurrent.Chan (newChan, writeChan)
-#endif
 
 import Hledger
 import Hledger.Cli hiding (progname,prognameandversion)
@@ -50,13 +46,11 @@ import Hledger.UI.RegisterScreen
 
 ----------------------------------------------------------------------
 
-#if MIN_VERSION_brick(0,16,0)
 newChan :: IO (BC.BChan a)
 newChan = BC.newBChan 10
 
 writeChan :: BC.BChan a -> a -> IO ()
 writeChan = BC.writeBChan
-#endif
 
 
 main :: IO ()
diff --git a/hledger-ui/Hledger/UI/UIState.hs b/hledger-ui/Hledger/UI/UIState.hs
index 3d0f8d76c..d7d4dc986 100644
--- a/hledger-ui/Hledger/UI/UIState.hs
+++ b/hledger-ui/Hledger/UI/UIState.hs
@@ -1,6 +1,5 @@
 {- | UIState operations. -}
 
-{-# LANGUAGE CPP               #-}
 {-# LANGUAGE NamedFieldPuns    #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
@@ -8,9 +7,6 @@
 module Hledger.UI.UIState
 where
 
-#if !MIN_VERSION_brick(0,19,0)
-import Brick
-#endif
 import Brick.Widgets.Edit
 import Data.List
 import Data.Text.Zipper (gotoEOL)
@@ -308,11 +304,7 @@ getDepth UIState{aopts=UIOpts{cliopts_=CliOpts{reportopts_=ropts}}} = depth_ rop
 showMinibuffer :: UIState -> UIState
 showMinibuffer ui = setMode (Minibuffer e) ui
   where
-#if MIN_VERSION_brick(0,19,0)
     e = applyEdit gotoEOL $ editor MinibufferEditor (Just 1) oldq
-#else
-    e = applyEdit gotoEOL $ editor MinibufferEditor (str . unlines) (Just 1) oldq
-#endif
     oldq = query_ $ reportopts_ $ cliopts_ $ aopts ui
 
 -- | Close the minibuffer, discarding any edit in progress.
diff --git a/hledger-ui/Hledger/UI/UIUtils.hs b/hledger-ui/Hledger/UI/UIUtils.hs
index d3c0a72cf..edc37509f 100644
--- a/hledger-ui/Hledger/UI/UIUtils.hs
+++ b/hledger-ui/Hledger/UI/UIUtils.hs
@@ -180,12 +180,7 @@ helpHandle ui ev = do
 minibuffer :: Editor String Name -> Widget Name
 minibuffer ed =
   forceAttr ("border" <> "minibuffer") $
-  hBox $
-#if MIN_VERSION_brick(0,19,0)
-  [txt "filter: ", renderEditor (str . unlines) True ed]
-#else
-  [txt "filter: ", renderEditor True ed]
-#endif
+  hBox [txt "filter: ", renderEditor (str . unlines) True ed]
 
 borderQueryStr :: String -> Widget Name
 borderQueryStr ""  = str ""
diff --git a/hledger/Hledger/Cli/Commands/Roi.hs b/hledger/Hledger/Cli/Commands/Roi.hs
index 2da60360b..f44b4e3d3 100644
--- a/hledger/Hledger/Cli/Commands/Roi.hs
+++ b/hledger/Hledger/Cli/Commands/Roi.hs
@@ -1,5 +1,5 @@
-{-# LANGUAGE ParallelListComp, CPP #-}
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE ParallelListComp #-}
+{-# LANGUAGE TemplateHaskell  #-}
 {-|
 
 The @roi@ command prints internal rate of return and time-weighted rate of return for and investment.
@@ -205,15 +205,10 @@ internalRateOfReturn showCashFlow prettyTables (OneSpan spanBegin spanEnd valueB
   -- 0% is always a solution, so require at least something here
   case totalCF of
     [] -> return 0
-    _ -> 
-      case ridders
-#if MIN_VERSION_math_functions(0,3,0)
-        (RiddersParam 100 (AbsTol 0.00001))
-#else
-        0.00001
-#endif
-        (0.000000000001,10000) (interestSum spanEnd totalCF) of
-        Root rate -> return ((rate-1)*100)
+    _ -> case ridders (RiddersParam 100 (AbsTol 0.00001))
+                      (0.000000000001,10000)
+                      (interestSum spanEnd totalCF) of
+        Root rate    -> return ((rate-1)*100)
         NotBracketed -> error' "Error: No solution -- not bracketed."  -- PARTIAL:
         SearchFailed -> error' "Error: Failed to find solution."