diff --git a/Ledger/Amount.hs b/Ledger/Amount.hs
index 5d306d94d..8846dcf29 100644
--- a/Ledger/Amount.hs
+++ b/Ledger/Amount.hs
@@ -136,7 +136,7 @@ sumAmounts :: [Amount] -> Amount
 sumAmounts = sum . filter (not . isZeroAmount)
 
 sumMixedAmounts :: [MixedAmount] -> MixedAmount
-sumMixedAmounts = concat
+sumMixedAmounts = normaliseMixedAmount . concat
 
 nullamt = []