diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+0.18.1
+------
+* Add the missing instance for `Data.Binary.Builder.Builder`.
+
 0.18.0.1
 --------
 * Added support for `base-4.9`
diff --git a/semigroups.cabal b/semigroups.cabal
--- a/semigroups.cabal
+++ b/semigroups.cabal
@@ -1,6 +1,6 @@
 name:          semigroups
 category:      Algebra, Data, Data Structures, Math
-version:       0.18.0.1
+version:       0.18.1
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
@@ -32,6 +32,14 @@
   default: True
   manual: True
 
+flag binary
+  description:
+    You can disable the use of the `binary` package using `-f-binary`.
+    .
+    Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
+  default: True
+  manual: True
+
 flag bytestring
   description:
     You can disable the use of the `bytestring` package using `-f-bytestring`.
@@ -72,6 +80,14 @@
   default: True
   manual: True
 
+flag transformers
+  description:
+    You can disable the use of the `transformers` package using `-f-transformers`.
+    .
+    Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sa    ndboxes for expert users.
+  default: True
+  manual: True
+
 flag unordered-containers
   description:
     You can disable the use of the `unordered-containers` package using `-f-unordered-containers`.
@@ -106,6 +122,9 @@
     if impl(ghc >= 7.4 && < 7.5)
       build-depends: ghc-prim
 
+    if flag(binary)
+      build-depends: binary
+
     if flag(bytestring)
       build-depends: bytestring >= 0.9 && < 1
 
@@ -126,3 +145,6 @@
 
     if flag(hashable) && flag(unordered-containers)
       build-depends: unordered-containers >= 0.2  && < 0.3
+
+    if flag(transformers)
+      build-depends: transformers >= 0.2 && < 0.6
diff --git a/src-ghc7/Data/Semigroup.hs b/src-ghc7/Data/Semigroup.hs
--- a/src-ghc7/Data/Semigroup.hs
+++ b/src-ghc7/Data/Semigroup.hs
@@ -126,6 +126,10 @@
 import Data.IntMap (IntMap)
 #endif
 
+#ifdef MIN_VERSION_binary
+import qualified Data.Binary.Builder as Builder
+#endif
+
 #ifdef MIN_VERSION_bytestring
 import Data.ByteString as Strict
 import Data.ByteString.Lazy as Lazy
@@ -141,6 +145,10 @@
 # endif
 #endif
 
+#if MIN_VERSION_base(4,8,0) || defined(MIN_VERSION_transformers)
+import Data.Functor.Identity
+#endif
+
 #if MIN_VERSION_base(4,7,0) || defined(MIN_VERSION_tagged)
 import Data.Proxy
 #endif
@@ -337,7 +345,7 @@
   stimes n (Product a) = Product (a ^ n)
 
 -- | This is a valid definition of 'stimes' for a 'Monoid'.
--- 
+--
 -- Unlike the default definition of 'stimes', it is defined for 0
 -- and so it should be preferred where possible.
 stimesMonoid :: (Integral b, Monoid a) => b -> a -> a
@@ -371,7 +379,7 @@
 -- When @x <> x = x@, this definition should be preferred, because it
 -- works in /O(1)/ rather than /O(log n)/.
 stimesIdempotent :: Integral b => b -> a -> a
-stimesIdempotent n x 
+stimesIdempotent n x
   | n <= 0 = error "stimesIdempotent: positive multiplier expected"
   | otherwise = x
 {-# INLINE stimesIdempotent #-}
@@ -787,6 +795,11 @@
 
 -- (==)/XNOR on Bool forms a 'Semigroup', but has no good name
 
+#ifdef MIN_VERSION_binary
+instance Semigroup Builder.Builder where
+  (<>) = mappend
+#endif
+
 #ifdef MIN_VERSION_bytestring
 instance Semigroup Strict.ByteString where
   (<>) = mappend
@@ -1007,6 +1020,16 @@
   stimes = stimesIdempotentMonoid
 #endif
 
+#if MIN_VERSION_base(4,8,0) || defined(MIN_VERSION_transformers)
+instance Semigroup a => Semigroup (Identity a) where
+# ifdef USE_COERCE
+  (<>) = coerce ((<>) :: a -> a -> a)
+# else
+  Identity a <> Identity b = Identity (a <> b)
+# endif
+  stimes n (Identity a) = Identity (stimes n a)
+#endif
+
 #if MIN_VERSION_base(4,7,0) || defined(MIN_VERSION_tagged)
 instance Semigroup (Proxy s) where
   _ <> _ = Proxy
@@ -1021,5 +1044,5 @@
 # else
   Tagged a <> Tagged b = Tagged (a <> b)
 # endif
-#endif
   stimes n (Tagged a) = Tagged (stimes n a)
+#endif