diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,6 +28,9 @@
     - env: CABALVER=1.24 GHCVER=8.0.2
       compiler: ": #GHC 8.0.2"
       addons: {apt: {packages: [cabal-install-1.24,ghc-8.0.2,hlint], sources: [hvr-ghc]}}
+    - env: CABALVER=2.0 GHCVER=8.2.1
+      compiler: ": #GHC 8.2.1"
+      addons: {apt: {packages: [cabal-install-2.0,ghc-8.2.1,hlint], sources: [hvr-ghc]}}
     - env: CABALVER=1.24 GHCVER=head
       compiler: ": #GHC head"
       addons: {apt: {packages: [cabal-install-1.24,ghc-head,hlint], sources: [hvr-ghc]}}
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,8 @@
+0.12
+----
+* Drop `safecopy` support
+* Removed some unused constraints.
+
 0.11.2
 ------
 * Support `doctest-0.12`
diff --git a/log-domain.cabal b/log-domain.cabal
--- a/log-domain.cabal
+++ b/log-domain.cabal
@@ -1,6 +1,6 @@
 name:          log-domain
 category:      Numeric
-version:       0.11.2
+version:       0.12
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
@@ -59,7 +59,6 @@
     hashable                  >= 1.2.5    && < 1.3,
     semigroupoids             >= 4        && < 6,
     semigroups                >= 0.8.4    && < 1,
-    safecopy                  >= 0.8.1    && < 0.10,
     vector                    >= 0.9      && < 0.13
 
   exposed-modules:
@@ -85,7 +84,7 @@
   else
     build-depends:
       base,
-      doctest        >= 0.11.1 && < 0.13,
+      doctest        >= 0.11.1 && < 0.14,
       generic-deriving,
       log-domain,
       semigroups     >= 0.9,
diff --git a/src/Numeric/Log.hs b/src/Numeric/Log.hs
--- a/src/Numeric/Log.hs
+++ b/src/Numeric/Log.hs
@@ -41,10 +41,8 @@
 import Data.Hashable.Lifted
 import Data.Int
 import Data.List as List hiding (sum)
-#if __GLASGOW_HASKELL__ < 710
-import Data.Monoid
-#endif
-import Data.SafeCopy
+import Data.List.NonEmpty (NonEmpty(..))
+import Data.Semigroup
 import Data.Semigroup.Foldable
 import Data.Semigroup.Traversable
 import Data.Serialize as Serialize
@@ -68,24 +66,6 @@
 -- | @Log@-domain @Float@ and @Double@ values.
 newtype Log a = Exp { ln :: a } deriving (Eq,Ord,Data,Typeable,Generic)
 
---deriveSafeCopy 1 'base ''Log
-
-instance SafeCopy a => SafeCopy (Log a) where
-      putCopy (Exp arg_afqB)
-        = contain
-            (do { safePut_a_afqC <- getSafePut;
-                  safePut_a_afqC arg_afqB;
-                  return () })
-      getCopy
-        = contain
-            (label
-               "Numeric.Log.Log:"
-               (do { safeGet_a_afqD <- getSafeGet;
-                     ((return Exp) <*> safeGet_a_afqD) }))
-      version = 1
-      kind = base
-      errorTypeName _ = "Numeric.Log.Log"
-
 instance (Floating a, Show a) => Show (Log a) where
   showsPrec d (Exp a) = T.showsPrec d (exp a)
 
@@ -345,7 +325,7 @@
   fromInteger = Exp . log . fromInteger
   {-# INLINE fromInteger #-}
 
-instance (Precise a, RealFloat a, Eq a) => Fractional (Log a) where
+instance (Precise a, RealFloat a) => Fractional (Log a) where
   -- n/0 == infinity is handled seamlessly for us, as is 0/0 and infinity/infinity NaNs, and 0/infinity == 0.
   Exp a / Exp b = Exp (a-b)
   {-# INLINE (/) #-}
@@ -370,7 +350,7 @@
 
 instance (RealFloat a, Unbox a) => Unbox (Log a)
 
-instance (RealFloat a, Unbox a) => M.MVector U.MVector (Log a) where
+instance Unbox a => M.MVector U.MVector (Log a) where
   {-# INLINE basicLength #-}
   {-# INLINE basicUnsafeSlice #-}
   {-# INLINE basicOverlaps #-}
@@ -421,21 +401,27 @@
 
 data Acc1 a = Acc1 {-# UNPACK #-} !Int64 !a
 
-instance (Precise a, RealFloat a) => Monoid (Log a) where
-  mempty  = Exp negInf
-  {-# INLINE mempty #-}
-  mappend = (+)
-  {-# INLINE mappend #-}
-  mconcat [] = 0
-  mconcat (Exp z:zs) = Exp $ case List.foldl' step1 (Acc1 0 z) zs of
+instance (Precise a, RealFloat a) => Semigroup (Log a) where
+  (<>) = (+)
+  {-# INLINE (<>) #-}
+  sconcat (Exp z :| zs) = Exp $ case List.foldl' step1 (Acc1 0 z) zs of
     Acc1 nm1 a
       | isInfinite a -> a
       | otherwise    -> a + log1p (List.foldl' (step2 a) 0 zs + fromIntegral nm1)
     where
       step1 (Acc1 n y) (Exp x) = Acc1 (n + 1) (max x y)
       step2 a r (Exp x) = r + expm1 (x - a)
-  {-# INLINE mconcat #-}
+  {-# INLINE sconcat #-}
 
+instance (Precise a, RealFloat a) => Monoid (Log a) where
+  mempty  = Exp negInf
+  {-# INLINE mempty #-}
+#if !(MIN_VERSION_base(4,11,0))
+  mappend = (<>)
+#endif
+  mconcat [] = 0
+  mconcat (x:xs) = sconcat (x :| xs)
+
 logMap :: Floating a => (a -> a) -> Log a -> Log a
 logMap f = Exp . log . f . exp . ln
 {-# INLINE logMap #-}
@@ -460,7 +446,7 @@
 -- True
 --
 -- /NB:/ This does require two passes over the data.
-sum :: (RealFloat a, Ord a, Precise a, Foldable f) => f (Log a) -> Log a
+sum :: (RealFloat a, Precise a, Foldable f) => f (Log a) -> Log a
 sum xs = Exp $ case Foldable.foldl' step1 None xs of
   None -> negInf
   Acc nm1 a
diff --git a/src/Numeric/Log/Signed.hs b/src/Numeric/Log/Signed.hs
--- a/src/Numeric/Log/Signed.hs
+++ b/src/Numeric/Log/Signed.hs
@@ -80,7 +80,7 @@
 instance (Show a, RealFloat a, Eq a, Fractional a) => Show (SignedLog a) where
   showsPrec d (SLExp s a) = (if not s && a /= negInf && not (isNaN a) then T.showChar '-' else id) . T.showsPrec d (exp a)
 
-instance (Precise a, RealFloat a, Fractional a, Read a) => Read (SignedLog a) where
+instance (Precise a, RealFloat a, Read a) => Read (SignedLog a) where
   readPrec = (realToFrac :: a -> SignedLog a) <$> step T.readPrec
 
 nxor :: Bool -> Bool -> Bool