diff --git a/hledger-lib/Hledger/Data/Types.hs b/hledger-lib/Hledger/Data/Types.hs
index 224355c21..19e4d4e07 100644
--- a/hledger-lib/Hledger/Data/Types.hs
+++ b/hledger-lib/Hledger/Data/Types.hs
@@ -464,7 +464,9 @@ data PriceGraph = PriceGraph {
     --   but those have to be Real for shortest path finding,
     --   so we'd have to transform them all first.
   }
-  deriving (Show)
+  deriving (Show,Generic)
+
+instance NFData PriceGraph
 
 -- | What kind of value conversion should be done on amounts ?
 -- UI: --value=cost|end|now|DATE[,COMM]
diff --git a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
index 432fa69ce..06e55502f 100644
--- a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE FlexibleInstances, RecordWildCards, ScopedTypeVariables, OverloadedStrings #-}
+{-# LANGUAGE FlexibleInstances, RecordWildCards, ScopedTypeVariables, OverloadedStrings, DeriveGeneric #-}
 {-|
 
 Multi-column balance reports, used by the balance command.
@@ -20,6 +20,8 @@ module Hledger.Reports.MultiBalanceReport (
 )
 where
 
+import GHC.Generics (Generic)
+import Control.DeepSeq (NFData)
 import Data.List
 import Data.Maybe
 import Data.Ord
@@ -69,9 +71,13 @@ newtype MultiBalanceReport =
                      ,[MultiBalanceReportRow]
                      ,MultiBalanceReportTotals
                      )
+  deriving (Generic)
+
 type MultiBalanceReportRow    = (AccountName, AccountName, Int, [MixedAmount], MixedAmount, MixedAmount)
 type MultiBalanceReportTotals = ([MixedAmount], MixedAmount, MixedAmount) -- (Totals list, sum of totals, average of totals)
 
+instance NFData MultiBalanceReport
+
 instance Show MultiBalanceReport where
     -- use pshow (pretty-show's ppShow) to break long lists onto multiple lines
     -- we add some bogus extra shows here to help it parse the output