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-aeson@ includes the same @aeson@ support
-  and tests that were present in @safe-money-0.6@.
+* This first release of `safe-money-aeson` includes the same @aeson@ support
+  and tests that were present in `safe-money-0.6`.
diff --git a/safe-money-aeson.cabal b/safe-money-aeson.cabal
--- a/safe-money-aeson.cabal
+++ b/safe-money-aeson.cabal
@@ -1,5 +1,5 @@
 name: safe-money-aeson
-version: 0.1
+version: 0.1.1
 license: BSD3
 license-file: LICENSE
 copyright: Copyright (c) Renzo Carbonara 2016-2018
@@ -34,7 +34,7 @@
   build-depends:
     aeson,
     base >=4.8 && <5.0,
-    safe-money >=0.7,
+    safe-money >=0.8,
     text
   exposed-modules:
     Money.Aeson
diff --git a/src/Money/Aeson.hs b/src/Money/Aeson.hs
--- a/src/Money/Aeson.hs
+++ b/src/Money/Aeson.hs
@@ -96,9 +96,9 @@
 -- string was dropped from the rendered 'Ae.Array').
 instance Ae.ToJSON Money.SomeDiscrete where
   toJSON = \sd ->
-    let r = Money.someDiscreteScale sd
+    let rs = Money.scaleToRational (Money.someDiscreteScale sd)
     in Ae.toJSON (MoneyI.someDiscreteCurrency' sd,
-                  numerator r, denominator r,
+                  numerator rs, denominator rs,
                   Money.someDiscreteAmount sd)
 
 -- | Compatible with 'Money.Discrete''
@@ -112,7 +112,9 @@
        ("Discrete" :: T.Text, c, n, d, a) <- Ae.parseJSON v
        pure (c, n, d, a)
     when (d == 0) (fail "denominator is zero")
-    maybe empty pure (MoneyI.mkSomeDiscrete' c (n % d) a)
+    maybe empty pure (MoneyI.mkSomeDiscrete' c
+                        <$> Money.scaleFromRational (n % d)
+                        <*> pure a)
 
 -- | Compatible with 'Money.SomeExchangeRate'
 --
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -58,10 +58,8 @@
 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")
@@ -123,7 +121,7 @@
 
 testDiscrete
   :: forall (currency :: Symbol) (unit :: Symbol)
-  .  ( Money.GoodScale (Money.Scale currency unit)
+  .  ( Money.GoodScale (Money.UnitScale currency unit)
      , KnownSymbol currency
      , KnownSymbol unit )
   => Proxy currency
@@ -149,9 +147,10 @@
       QC.forAll QC.arbitrary $ \(x :: Money.Discrete currency unit) ->
         let sx = Money.toSomeDiscrete x
             c = T.unpack (Money.someDiscreteCurrency sx)
-            r = Money.someDiscreteScale sx
+            rs = Money.scaleToRational (Money.someDiscreteScale sx)
             a = Money.someDiscreteAmount sx
-            bs = Ae.encode ("Discrete" :: String, c, numerator r, denominator r, a)
+            bs = Ae.encode ("Discrete" :: String, c, numerator rs,
+                            denominator rs, a)
         in (Just  x === Ae.decode bs) .&&.
            (Just sx === Ae.decode bs)
   ]