diff --git a/src/lib/Witch/Instances.hs b/src/lib/Witch/Instances.hs
--- a/src/lib/Witch/Instances.hs
+++ b/src/lib/Witch/Instances.hs
@@ -29,6 +29,7 @@
 import qualified Data.Text.Lazy.Encoding as LazyText
 import qualified Data.Typeable as Typeable
 import qualified Data.Word as Word
+import qualified GHC.Float as Float
 import qualified Numeric.Natural as Natural
 import qualified Witch.Cast as Cast
 import qualified Witch.TryCast as TryCast
@@ -804,9 +805,9 @@
       then if s > 0 then Left Exception.Overflow else Left Exception.Underflow
       else Right $ toRational s
 
--- | Uses 'realToFrac'.
+-- | Uses 'Float.double2Float'.
 instance Cast.Cast Float Double where
-  cast = realToFrac
+  cast = Float.float2Double
 
 -- Double
 
@@ -872,9 +873,9 @@
       then if s > 0 then Left Exception.Overflow else Left Exception.Underflow
       else Right $ toRational s
 
--- | Uses 'realToFrac'. This necessarily loses some precision.
+-- | Uses 'Float.double2Float'. This necessarily loses some precision.
 instance Cast.Cast Double Float where
-  cast = realToFrac
+  cast = Float.double2Float
 
 -- Ratio
 
@@ -1076,8 +1077,12 @@
 
 -- TryCastException
 
-instance Cast.Cast (TryCastException.TryCastException s t0) (TryCastException.TryCastException s t1)
+-- | Uses @coerce@.
+instance Cast.Cast
+  (TryCastException.TryCastException s u)
+  (TryCastException.TryCastException s t)
 
+-- | Uses 'show'.
 instance
   ( Show s
   , Typeable.Typeable s
@@ -1085,6 +1090,7 @@
   ) => Cast.Cast (TryCastException.TryCastException s t) String where
   cast = show
 
+-- | Converts via 'String'.
 instance
   ( Show s
   , Typeable.Typeable s
@@ -1092,6 +1098,7 @@
   ) => Cast.Cast (TryCastException.TryCastException s t) Text.Text where
   cast = Utility.via @String
 
+-- | Converts via 'String'.
 instance
   ( Show s
   , Typeable.Typeable s
diff --git a/src/lib/Witch/TryCastException.hs b/src/lib/Witch/TryCastException.hs
--- a/src/lib/Witch/TryCastException.hs
+++ b/src/lib/Witch/TryCastException.hs
@@ -8,7 +8,9 @@
 
 -- | This exception is thrown when a @TryCast@ conversion fails. It has the
 -- original @source@ value that caused the failure and it knows the @target@
--- type it was trying to convert into.
+-- type it was trying to convert into. It also has an optional
+-- 'Exception.SomeException' for communicating what went wrong while
+-- converting.
 data TryCastException source target = TryCastException
   source
   (Maybe Exception.SomeException)
@@ -20,10 +22,11 @@
   ) => Show (TryCastException source target) where
   showsPrec d (TryCastException x e) =
     showParen (d > 10)
-      $ showString "TryCastException {- "
-      . shows
-          (Typeable.typeRep (Proxy.Proxy :: Proxy.Proxy (source -> target)))
-      . showString " -} "
+      $ showString "TryCastException @"
+      . showsPrec 11 (Typeable.typeRep (Proxy.Proxy :: Proxy.Proxy source))
+      . showString " @"
+      . showsPrec 11 (Typeable.typeRep (Proxy.Proxy :: Proxy.Proxy target))
+      . showChar ' '
       . showsPrec 11 x
       . showChar ' '
       . showsPrec 11 e
diff --git a/src/test/Main.hs b/src/test/Main.hs
--- a/src/test/Main.hs
+++ b/src/test/Main.hs
@@ -1643,16 +1643,17 @@
       Hspec.it "needs tests" Hspec.pending
 
     Hspec.describe "Cast (TryCastException s t) String" $ do
+      test $ Witch.cast (Witch.TryCastException Nothing Nothing :: Witch.TryCastException (Maybe Bool) (Maybe Int)) `Hspec.shouldBe` "TryCastException @(Maybe Bool) @(Maybe Int) Nothing Nothing"
       let f = Witch.cast @(Witch.TryCastException Bool Int) @String
-      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` "TryCastException {- Bool -> Int -} False Nothing"
+      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` "TryCastException @Bool @Int False Nothing"
 
     Hspec.describe "Cast (TryCastException s t) Text" $ do
       let f = Witch.cast @(Witch.TryCastException Bool Int) @Text.Text
-      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` Text.pack "TryCastException {- Bool -> Int -} False Nothing"
+      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` Text.pack "TryCastException @Bool @Int False Nothing"
 
     Hspec.describe "Cast (TryCastException s t) LazyText" $ do
       let f = Witch.cast @(Witch.TryCastException Bool Int) @LazyText.Text
-      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` LazyText.pack "TryCastException {- Bool -> Int -} False Nothing"
+      test $ f (Witch.TryCastException False Nothing) `Hspec.shouldBe` LazyText.pack "TryCastException @Bool @Int False Nothing"
 
 test :: Hspec.Example a => a -> Hspec.SpecWith (Hspec.Arg a)
 test = Hspec.it ""
diff --git a/witch.cabal b/witch.cabal
--- a/witch.cabal
+++ b/witch.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.2
 
 name: witch
-version: 0.2.0.0
+version: 0.2.0.1
 synopsis: Convert values from one type into another.
 description: Witch converts values from one type into another.