diff --git a/hledger-lib/Hledger/Data/Types.hs b/hledger-lib/Hledger/Data/Types.hs
index 7b7f266b4..4d1f63b15 100644
--- a/hledger-lib/Hledger/Data/Types.hs
+++ b/hledger-lib/Hledger/Data/Types.hs
@@ -28,7 +28,6 @@ module Hledger.Data.Types
 where
 
 import GHC.Generics (Generic)
-import Control.DeepSeq (NFData)
 import Data.Decimal
 import Data.Default
 import Data.Functor (($>))
@@ -79,8 +78,6 @@ data DateSpan = DateSpan (Maybe Day) (Maybe Day) deriving (Eq,Ord,Generic)
 
 instance Default DateSpan where def = DateSpan Nothing Nothing
 
-instance NFData DateSpan
-
 -- synonyms for various date-related scalars
 type Year = Integer
 type Month = Int     -- 1-12
@@ -135,8 +132,6 @@ data Interval =
 
 instance Default Interval where def = NoInterval
 
-instance NFData Interval
-
 type AccountName = Text
 
 data AccountType =
@@ -148,8 +143,6 @@ data AccountType =
   | Cash  -- ^ a subtype of Asset - liquid assets to show in cashflow report
   deriving (Show,Eq,Ord,Generic)
 
-instance NFData AccountType
-
 -- not worth the trouble, letters defined in accountdirectivep for now
 --instance Read AccountType
 --  where
@@ -164,12 +157,8 @@ data AccountAlias = BasicAlias AccountName AccountName
                   | RegexAlias Regexp Replacement
   deriving (Eq, Read, Show, Ord, Generic)
 
--- instance NFData AccountAlias
-
 data Side = L | R deriving (Eq,Show,Read,Ord,Generic)
 
-instance NFData Side
-
 -- | The basic numeric type used in amounts.
 type Quantity = Decimal
 -- The following is for hledger-web, and requires blaze-markup.
@@ -184,8 +173,6 @@ instance ToMarkup Quantity
 data AmountPrice = UnitPrice Amount | TotalPrice Amount
   deriving (Eq,Ord,Generic,Show)
 
-instance NFData AmountPrice
-
 -- | Display style for an amount.
 data AmountStyle = AmountStyle {
       ascommodityside   :: Side,                 -- ^ does the symbol appear on the left or the right ?
@@ -195,8 +182,6 @@ data AmountStyle = AmountStyle {
       asdigitgroups     :: Maybe DigitGroupStyle -- ^ style for displaying digit groups, if any
 } deriving (Eq,Ord,Read,Generic)
 
-instance NFData AmountStyle
-
 instance Show AmountStyle where
   show AmountStyle{..} =
     printf "AmountStylePP \"%s %s %s %s %s..\""
@@ -208,8 +193,6 @@ instance Show AmountStyle where
 
 data AmountPrecision = Precision !Word8 | NaturalPrecision deriving (Eq,Ord,Read,Show,Generic)
 
-instance NFData AmountPrecision
-
 -- | A style for displaying digit groups in the integer part of a
 -- floating point number. It consists of the character used to
 -- separate groups (comma or period, whichever is not used as decimal
@@ -219,8 +202,6 @@ instance NFData AmountPrecision
 data DigitGroupStyle = DigitGroups Char [Word8]
   deriving (Eq,Ord,Read,Show,Generic)
 
-instance NFData DigitGroupStyle
-
 type CommoditySymbol = Text
 
 data Commodity = Commodity {
@@ -228,8 +209,6 @@ data Commodity = Commodity {
   cformat :: Maybe AmountStyle
   } deriving (Show,Eq,Generic) --,Ord)
 
-instance NFData Commodity
-
 data Amount = Amount {
       acommodity  :: CommoditySymbol,   -- commodity symbol, or special value "AUTO"
       aquantity   :: Quantity,          -- numeric quantity, or zero in case of "AUTO"
@@ -239,17 +218,11 @@ data Amount = Amount {
       aprice      :: Maybe AmountPrice  -- ^ the (fixed, transaction-specific) price for this amount, if any
     } deriving (Eq,Ord,Generic,Show)
 
-instance NFData Amount
-
 newtype MixedAmount = Mixed [Amount] deriving (Eq,Ord,Generic,Show)
 
-instance NFData MixedAmount
-
 data PostingType = RegularPosting | VirtualPosting | BalancedVirtualPosting
                    deriving (Eq,Show,Generic)
 
-instance NFData PostingType
-
 type TagName = Text
 type TagValue = Text
 type Tag = (TagName, TagValue)  -- ^ A tag name and (possibly empty) value.
@@ -260,8 +233,6 @@ type DateTag = (TagName, Day)
 data Status = Unmarked | Pending | Cleared
   deriving (Eq,Ord,Bounded,Enum,Generic)
 
-instance NFData Status
-
 instance Show Status where -- custom show.. bad idea.. don't do it..
   show Unmarked = ""
   show Pending   = "!"
@@ -311,8 +282,6 @@ data BalanceAssertion = BalanceAssertion {
       baposition  :: GenericSourcePos    -- ^ the assertion's file position, for error reporting
     } deriving (Eq,Generic,Show)
 
-instance NFData BalanceAssertion
-
 data Posting = Posting {
       pdate             :: Maybe Day,         -- ^ this posting's date, if different from the transaction's
       pdate2            :: Maybe Day,         -- ^ this posting's secondary date, if different from the transaction's
@@ -332,8 +301,6 @@ data Posting = Posting {
                                                     --   untransformed posting (which will have Nothing in this field).
     } deriving (Generic)
 
-instance NFData Posting
-
 -- The equality test for postings ignores the parent transaction's
 -- identity, to avoid recurring ad infinitum.
 -- XXX could check that it's Just or Nothing.
@@ -362,8 +329,6 @@ data GenericSourcePos = GenericSourcePos FilePath Int Int    -- ^ file path, 1-b
                       | JournalSourcePos FilePath (Int, Int) -- ^ file path, inclusive range of 1-based line numbers (first, last).
   deriving (Eq, Read, Show, Ord, Generic)
 
-instance NFData GenericSourcePos
-
 --{-# ANN Transaction "HLint: ignore" #-}
 --    Ambiguous type variable ‘p0’ arising from an annotation
 --    prevents the constraint ‘(Data p0)’ from being solved.
@@ -382,8 +347,6 @@ data Transaction = Transaction {
       tpostings                :: [Posting]  -- ^ this transaction's postings
     } deriving (Eq,Generic,Show)
 
-instance NFData Transaction
-
 -- | A transaction modifier rule. This has a query which matches postings
 -- in the journal, and a list of transformations to apply to those
 -- postings or their transactions. Currently there is one kind of transformation:
@@ -394,8 +357,6 @@ data TransactionModifier = TransactionModifier {
       tmpostingrules :: [TMPostingRule]
     } deriving (Eq,Generic,Show)
 
-instance NFData TransactionModifier
-
 nulltransactionmodifier = TransactionModifier{
   tmquerytxt = ""
  ,tmpostingrules = []
@@ -433,12 +394,8 @@ nullperiodictransaction = PeriodicTransaction{
      ,ptpostings     = []
 }
 
-instance NFData PeriodicTransaction
-
 data TimeclockCode = SetBalance | SetRequiredHours | In | Out | FinalOut deriving (Eq,Ord,Generic)
 
-instance NFData TimeclockCode
-
 data TimeclockEntry = TimeclockEntry {
       tlsourcepos   :: GenericSourcePos,
       tlcode        :: TimeclockCode,
@@ -447,8 +404,6 @@ data TimeclockEntry = TimeclockEntry {
       tldescription :: Text
     } deriving (Eq,Ord,Generic)
 
-instance NFData TimeclockEntry
-
 -- | A market price declaration made by the journal format's P directive.
 -- It declares two things: a historical exchange rate between two commodities,
 -- and an amount display style for the second commodity.
@@ -459,8 +414,6 @@ data PriceDirective = PriceDirective {
   } deriving (Eq,Ord,Generic,Show)
         -- Show instance derived in Amount.hs (XXX why ?)
 
-instance NFData PriceDirective
-
 -- | A historical market price (exchange rate) from one commodity to another.
 -- A more concise form of a PriceDirective, without the amount display info.
 data MarketPrice = MarketPrice {
@@ -471,8 +424,6 @@ data MarketPrice = MarketPrice {
   } deriving (Eq,Ord,Generic)
         -- Show instance derived in Amount.hs (XXX why ?)
 
-instance NFData MarketPrice
-
 -- additional valuation-related types in Valuation.hs
 
 -- | A Journal, containing transactions and various other things.
@@ -512,8 +463,6 @@ data Journal = Journal {
   } deriving (Eq, Generic)
 
 deriving instance Generic ClockTime
-instance NFData ClockTime
--- instance NFData Journal
 
 -- | A journal in the process of being parsed, not yet finalised.
 -- The data is partial, and list fields are in reverse order.
@@ -532,8 +481,6 @@ data AccountDeclarationInfo = AccountDeclarationInfo {
                                  --   relative to other account declarations, during parsing (1..)
 } deriving (Eq,Show,Generic)
 
-instance NFData AccountDeclarationInfo
-
 nullaccountdeclarationinfo = AccountDeclarationInfo {
    adicomment          = ""
   ,aditags             = []
diff --git a/hledger-lib/Hledger/Data/Valuation.hs b/hledger-lib/Hledger/Data/Valuation.hs
index 506beeb89..2c2ec534e 100644
--- a/hledger-lib/Hledger/Data/Valuation.hs
+++ b/hledger-lib/Hledger/Data/Valuation.hs
@@ -28,7 +28,6 @@ module Hledger.Data.Valuation (
 where
 
 import Control.Applicative ((<|>))
-import Control.DeepSeq (NFData)
 import Data.Decimal (roundTo)
 import Data.Function ((&), on)
 import Data.Graph.Inductive  (Gr, Node, NodeMap, mkMapGraph, mkNode, lab, out, sp)
@@ -86,8 +85,6 @@ data PriceGraph = PriceGraph {
   }
   deriving (Show,Generic)
 
-instance NFData PriceGraph
-
 -- | A price oracle is a magic memoising function that efficiently
 -- looks up market prices (exchange rates) from one commodity to
 -- another (or if unspecified, to a default valuation commodity) on a
diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index 0424305c9..281467513 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -1,10 +1,10 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.34.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: ca2b9f025d75c0b65f91b2e5fe7203d00d1d9f8c423c8c4f0cb7675df848a5aa
+-- hash: e8ee8c99329f53fe86ae9df138d05c8c39726a66da2ad1da3ae27500c45b2591
 
 name:           hledger-lib
 version:        1.18.99
@@ -124,7 +124,6 @@ library
     , cmdargs >=0.10
     , containers
     , data-default >=0.5
-    , deepseq
     , directory
     , extra >=1.6.3
     , fgl >=5.5.4.0
@@ -177,7 +176,6 @@ test-suite doctest
     , cmdargs >=0.10
     , containers
     , data-default >=0.5
-    , deepseq
     , directory
     , doctest >=0.16.3
     , extra >=1.6.3
@@ -233,7 +231,6 @@ test-suite unittest
     , cmdargs >=0.10
     , containers
     , data-default >=0.5
-    , deepseq
     , directory
     , extra >=1.6.3
     , fgl >=5.5.4.0
diff --git a/hledger-lib/package.yaml b/hledger-lib/package.yaml
index 1353382b8..35c6092e1 100644
--- a/hledger-lib/package.yaml
+++ b/hledger-lib/package.yaml
@@ -59,7 +59,6 @@ dependencies:
 - cassava-megaparsec
 - data-default >=0.5
 - Decimal >=0.5.1
-- deepseq
 - directory
 - fgl >=5.5.4.0
 - file-embed >=0.0.10