diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,4 +1,9 @@
+# Version 0.1.1
+
+* Require `safe-money>=0.8`.
+
+
 # Version 0.1
 
-* This first release of @safe-money-serialise@ includes the same
-  @serialise@ support and tests that were present in @safe-money-0.6@.
+* This first release of `safe-money-serialise` includes the same
+  `serialise` support and tests that were present in `safe-money-0.6`.
diff --git a/safe-money-serialise.cabal b/safe-money-serialise.cabal
--- a/safe-money-serialise.cabal
+++ b/safe-money-serialise.cabal
@@ -1,5 +1,5 @@
 name: safe-money-serialise
-version: 0.1
+version: 0.1.1
 license: BSD3
 license-file: LICENSE
 copyright: Copyright (c) Renzo Carbonara 2016-2018
@@ -33,7 +33,7 @@
   build-depends:
     base (>=4.8 && <5.0),
     bytestring,
-    safe-money,
+    safe-money >=0.8,
     serialise
   exposed-modules:
     Money.Serialise
diff --git a/src/Money/Serialise.hs b/src/Money/Serialise.hs
--- a/src/Money/Serialise.hs
+++ b/src/Money/Serialise.hs
@@ -42,6 +42,17 @@
   decode = maybe (fail "ExchangeRate") pure
              =<< fmap Money.fromSomeExchangeRate Ser.decode
 
+instance Ser.Serialise Money.Scale where
+  encode = \s ->
+    let r = Money.scaleToRational s
+    in Ser.encode (numerator r) <>
+       Ser.encode (denominator r)
+  decode = maybe (fail "Scale") pure =<< do
+    n :: Integer <- Ser.decode
+    d :: Integer <- Ser.decode
+    when (d == 0) (fail "denominator is zero")
+    pure (MoneyI.scaleFromRational (n % d))
+
 -- | Compatible with 'Money.Dense'.
 instance Ser.Serialise Money.SomeDense where
   encode = \sd ->
@@ -59,18 +70,14 @@
 -- | Compatible with 'Money.Discrete'.
 instance Ser.Serialise Money.SomeDiscrete where
   encode = \sd ->
-    let r = Money.someDiscreteScale sd
-    in Ser.encode (MoneyI.someDiscreteCurrency' sd) <>
-       Ser.encode (numerator r) <>
-       Ser.encode (denominator r) <>
-       Ser.encode (Money.someDiscreteAmount sd)
-  decode = maybe (fail "SomeDiscrete") pure =<< do
+    Ser.encode (MoneyI.someDiscreteCurrency' sd) <>
+    Ser.encode (Money.someDiscreteScale sd) <>
+    Ser.encode (Money.someDiscreteAmount sd)
+  decode = do
     c :: String <- Ser.decode
-    n :: Integer <- Ser.decode
-    d :: Integer <- Ser.decode
-    when (d == 0) (fail "denominator is zero")
+    s :: Money.Scale <- Ser.decode
     a :: Integer <- Ser.decode
-    pure (MoneyI.mkSomeDiscrete' c (n % d) a)
+    pure (MoneyI.mkSomeDiscrete' c s a)
 
 -- | Compatible with 'Money.ExchangeRate'.
 instance Ser.Serialise Money.SomeExchangeRate where
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -55,10 +55,8 @@
 testCurrencyUnits :: Tasty.TestTree
 testCurrencyUnits =
   Tasty.testGroup "Currency units"
-  [ testDiscrete (Proxy :: Proxy "BTC") (Proxy :: Proxy "BTC")
-  , testDiscrete (Proxy :: Proxy "BTC") (Proxy :: Proxy "satoshi")
+  [ testDiscrete (Proxy :: Proxy "BTC") (Proxy :: Proxy "satoshi")
   , testDiscrete (Proxy :: Proxy "BTC") (Proxy :: Proxy "bitcoin")
-  , testDiscrete (Proxy :: Proxy "USD") (Proxy :: Proxy "USD")
   , testDiscrete (Proxy :: Proxy "USD") (Proxy :: Proxy "cent")
   , testDiscrete (Proxy :: Proxy "USD") (Proxy :: Proxy "dollar")
   , testDiscrete (Proxy :: Proxy "VUV") (Proxy :: Proxy "vatu")
@@ -112,7 +110,7 @@
 
 testDiscrete
   :: forall (currency :: Symbol) (unit :: Symbol)
-  .  ( Money.GoodScale (Money.Scale currency unit)
+  .  ( Money.GoodScale (Money.UnitScale currency unit)
      , KnownSymbol currency
      , KnownSymbol unit )
   => Proxy currency