diff --git a/hledger-lib/Hledger/Data/Json.hs b/hledger-lib/Hledger/Data/Json.hs
index 24af88176..3f526a143 100644
--- a/hledger-lib/Hledger/Data/Json.hs
+++ b/hledger-lib/Hledger/Data/Json.hs
@@ -28,15 +28,20 @@ JSON instances. Should they be in Types.hs ?
 module Hledger.Data.Json (
   -- * Instances
   -- * Utilities
-   readJsonFile
+   toJsonText
   ,writeJsonFile
+  ,readJsonFile
 ) where
 
 import           Data.Aeson
+import           Data.Aeson.Encode.Pretty (encodePrettyToTextBuilder)
 --import           Data.Aeson.TH
 import qualified Data.ByteString.Lazy as BL
 import           Data.Decimal
 import           Data.Maybe
+import qualified Data.Text.Lazy    as TL
+import qualified Data.Text.Lazy.IO as TL
+import           Data.Text.Lazy.Builder (toLazyText)
 import           GHC.Generics (Generic)
 import           System.Time (ClockTime)
 
@@ -201,17 +206,24 @@ instance FromJSON (DecimalRaw Integer)
 
 -- Utilities
 
--- | Read a json from a file and decode/parse it as the target type, if we can.
--- Example: >>> readJsonFile "in.json" :: IO MixedAmount
+-- | Show a JSON-convertible haskell value as pretty-printed JSON text.
+toJsonText :: ToJSON a => a -> TL.Text
+toJsonText = (<>"\n") . toLazyText . encodePrettyToTextBuilder
+
+-- | Write a JSON-convertible haskell value to a pretty-printed JSON file.
+-- Eg: writeJsonFile "a.json" nulltransaction
+writeJsonFile :: ToJSON a => FilePath -> a -> IO ()
+writeJsonFile f = TL.writeFile f . toJsonText
+-- we write with Text and read with ByteString, is that fine ?
+
+-- | Read a JSON file and decode it to the target type, or raise an error if we can't.
+-- Eg: readJsonFile "a.json" :: IO Transaction
 readJsonFile :: FromJSON a => FilePath -> IO a
 readJsonFile f = do
-  bs <- BL.readFile f
-  let v = fromMaybe (error "could not decode bytestring as json value") (decode bs :: Maybe Value)
+  bl <- BL.readFile f
+  let v = fromMaybe (error $ "could not decode JSON in "++show f++" to target value")
+          (decode bl :: Maybe Value)
   case fromJSON v :: FromJSON a => Result a of
     Error e   -> error e
     Success t -> return t
 
--- | Write some to-JSON-convertible haskell value to a json file, if we can.
--- Example: >>> writeJsonFile "out.json" nullmixedamt
-writeJsonFile :: ToJSON a => FilePath -> a -> IO ()
-writeJsonFile f v = BL.writeFile f (encode v)
diff --git a/hledger-lib/Hledger/Utils/Text.hs b/hledger-lib/Hledger/Utils/Text.hs
index c4bf0b393..cabe127a1 100644
--- a/hledger-lib/Hledger/Utils/Text.hs
+++ b/hledger-lib/Hledger/Utils/Text.hs
@@ -26,7 +26,6 @@ module Hledger.Utils.Text
   stripquotes,
  -- isSingleQuoted,
  -- isDoubleQuoted,
-  jsonPrettyText,
  -- -- * single-line layout
   textstrip,
   textlstrip,
@@ -60,8 +59,6 @@ module Hledger.Utils.Text
   )
 where
 
-import Data.Aeson (Value)
-import Data.Aeson.Encode.Pretty (encodePrettyToTextBuilder)
 -- import Data.Char
 import Data.List
 #if !(MIN_VERSION_base(4,11,0))
@@ -69,8 +66,6 @@ import Data.Monoid
 #endif
 import Data.Text (Text)
 import qualified Data.Text as T
-import qualified Data.Text.Lazy as TL
-import Data.Text.Lazy.Builder (toLazyText)
 -- import Text.Parsec
 -- import Text.Printf (printf)
 
@@ -83,10 +78,6 @@ import Hledger.Utils.Test
 -- lowercase = map toLower
 -- uppercase = map toUpper
 
--- | Pretty-print a JSON value.
-jsonPrettyText :: Value -> TL.Text
-jsonPrettyText = toLazyText . encodePrettyToTextBuilder
-
 -- | Remove leading and trailing whitespace.
 textstrip :: Text -> Text
 textstrip = textlstrip . textrstrip
diff --git a/hledger/Hledger/Cli/Commands/Balance.hs b/hledger/Hledger/Cli/Commands/Balance.hs
index dc9b5acfe..e20b839fa 100644
--- a/hledger/Hledger/Cli/Commands/Balance.hs
+++ b/hledger/Hledger/Cli/Commands/Balance.hs
@@ -253,7 +253,6 @@ module Hledger.Cli.Commands.Balance (
  ,tests_Balance
 ) where
 
-import Data.Aeson (toJSON)
 import Data.List
 import Data.Maybe
 --import qualified Data.Map as Map
@@ -320,7 +319,7 @@ balance opts@CliOpts{rawopts_=rawopts,reportopts_=ropts@ReportOpts{..}} j = do
                 assrt          = not $ ignore_assertions_ $ inputopts_ opts
             render = case fmt of
               "txt"  -> budgetReportAsText ropts
-              "json" -> (++"\n") . TL.unpack . jsonPrettyText . toJSON
+              "json" -> (++"\n") . TL.unpack . toJsonText
               _      -> const $ error' $ unsupportedOutputFormatError fmt
         writeOutput opts $ render budgetreport
 
@@ -331,7 +330,7 @@ balance opts@CliOpts{rawopts_=rawopts,reportopts_=ropts@ReportOpts{..}} j = do
                 "txt"  -> multiBalanceReportAsText ropts
                 "csv"  -> (++"\n") . printCSV . multiBalanceReportAsCsv ropts
                 "html" -> (++"\n") . TL.unpack . L.renderText . multiBalanceReportAsHtml ropts
-                "json" -> (++"\n") . TL.unpack . jsonPrettyText . toJSON
+                "json" -> (++"\n") . TL.unpack . toJsonText
                 _      -> const $ error' $ unsupportedOutputFormatError fmt
           writeOutput opts $ render report
 
@@ -346,7 +345,7 @@ balance opts@CliOpts{rawopts_=rawopts,reportopts_=ropts@ReportOpts{..}} j = do
               render = case fmt of
                 "txt"  -> balanceReportAsText
                 "csv"  -> \ropts r -> (++ "\n") $ printCSV $ balanceReportAsCsv ropts r
-                "json" -> const $ (++"\n") . TL.unpack . jsonPrettyText . toJSON
+                "json" -> const $ (++"\n") . TL.unpack . toJsonText
                 _      -> const $ error' $ unsupportedOutputFormatError fmt
           writeOutput opts $ render ropts report
 
diff --git a/hledger/Hledger/Cli/Commands/Print.hs b/hledger/Hledger/Cli/Commands/Print.hs
index 9ce9c896c..00f8b88d6 100644
--- a/hledger/Hledger/Cli/Commands/Print.hs
+++ b/hledger/Hledger/Cli/Commands/Print.hs
@@ -15,7 +15,6 @@ module Hledger.Cli.Commands.Print (
 )
 where
 
-import Data.Aeson (toJSON)
 import Data.Maybe (isJust)
 import Data.Text (Text)
 import qualified Data.Text as T
@@ -60,7 +59,7 @@ printEntries opts@CliOpts{reportopts_=ropts} j = do
       render = case fmt of
         "txt"  -> entriesReportAsText opts
         "csv"  -> (++"\n") . printCSV . entriesReportAsCsv
-        "json" -> (++"\n") . TL.unpack . jsonPrettyText . toJSON
+        "json" -> (++"\n") . TL.unpack . toJsonText
         _      -> const $ error' $ unsupportedOutputFormatError fmt
   writeOutput opts $ render $ entriesReport ropts q j
 
diff --git a/hledger/Hledger/Cli/Commands/Register.hs b/hledger/Hledger/Cli/Commands/Register.hs
index 54b04fe10..ca157d178 100644
--- a/hledger/Hledger/Cli/Commands/Register.hs
+++ b/hledger/Hledger/Cli/Commands/Register.hs
@@ -18,7 +18,6 @@ module Hledger.Cli.Commands.Register (
  ,tests_Register
 ) where
 
-import Data.Aeson (toJSON)
 import Data.List
 import Data.Maybe
 -- import Data.Text (Text)
@@ -64,7 +63,7 @@ register opts@CliOpts{reportopts_=ropts} j = do
   let fmt = outputFormatFromOpts opts
       render | fmt=="txt"  = postingsReportAsText
              | fmt=="csv"  = const ((++"\n") . printCSV . postingsReportAsCsv)
-             | fmt=="json" = const ((++"\n") . TL.unpack . jsonPrettyText . toJSON)
+             | fmt=="json" = const ((++"\n") . TL.unpack . toJsonText)
              | otherwise   = const $ error' $ unsupportedOutputFormatError fmt
   writeOutput opts $ render opts $ postingsReport ropts (queryFromOpts d ropts) j
 
diff --git a/hledger/Hledger/Cli/CompoundBalanceCommand.hs b/hledger/Hledger/Cli/CompoundBalanceCommand.hs
index 8080a076a..f5da989a6 100644
--- a/hledger/Hledger/Cli/CompoundBalanceCommand.hs
+++ b/hledger/Hledger/Cli/CompoundBalanceCommand.hs
@@ -13,7 +13,6 @@ module Hledger.Cli.CompoundBalanceCommand (
  ,compoundBalanceCommand
 ) where
 
-import Data.Aeson (toJSON)
 import Data.List (foldl')
 import Data.Maybe
 import qualified Data.Text as TS
@@ -240,7 +239,7 @@ compoundBalanceCommand CompoundBalanceCommandSpec{..} opts@CliOpts{reportopts_=r
         "txt"  -> compoundBalanceReportAsText ropts' cbr
         "csv"  -> printCSV (compoundBalanceReportAsCsv ropts cbr) ++ "\n"
         "html" -> (++"\n") $ TL.unpack $ L.renderText $ compoundBalanceReportAsHtml ropts cbr
-        "json" -> (++"\n") $ TL.unpack $ jsonPrettyText $ toJSON cbr
+        "json" -> (++"\n") $ TL.unpack $ toJsonText cbr
         _      -> error' $ unsupportedOutputFormatError fmt
 
 -- | Summarise one or more (inclusive) end dates, in a way that's