diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,7 @@
+0.0.3
+
+* Change the `degrees` iso.
+
 0.0.2
 
 * More instances for `Radian`.
diff --git a/radian.cabal b/radian.cabal
--- a/radian.cabal
+++ b/radian.cabal
@@ -1,5 +1,5 @@
 name:               radian
-version:            0.0.2
+version:            0.0.3
 license:            BSD3
 license-file:       LICENCE
 author:             Tony Morris <ʇǝu˙sıɹɹoɯʇ@ןןǝʞsɐɥ>
diff --git a/src/Data/Radian.hs b/src/Data/Radian.hs
--- a/src/Data/Radian.hs
+++ b/src/Data/Radian.hs
@@ -7,7 +7,7 @@
 , degrees
 ) where
 
-import Control.Lens(Iso, iso, from)
+import Control.Lens(Iso, iso)
 import Data.Eq(Eq)
 import Data.Ord(Ord)
 import Prelude(Show, Num((*)), Fractional((/)), Floating, Real, RealFrac, RealFloat, pi)
@@ -50,27 +50,10 @@
     (\(Radian a) -> a / pi * 180)
     (\a -> Radian (a / 180 * pi))
 
--- | An isomorphism from degrees to radians.
---
--- >>> degrees # (3.14 :: Radian Double)
--- 179.90874767107852
---
--- >>> degrees # (1 :: Radian Double)
--- 57.29577951308232
---
--- >>> degrees # (10 :: Radian Double)
--- 572.9577951308232
---
--- >>> degrees # (0 :: Radian Double)
--- 0.0
---
--- >>> degrees # (-1 :: Radian Double)
--- -57.29577951308232
---
--- >>> degrees # (-3 :: Radian Double)
--- -171.88733853924697
 degrees ::
   (Floating a, Floating b) =>
-  Iso a b (Radian a) (Radian b)
+  Iso (Radian a) (Radian b) a b
 degrees =
-  from radians
+  iso
+    (\(Radian a) -> a)
+    Radian