diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -4,6 +4,12 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to the [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
+## [0.4.4] - 2018-03-23
+### Added
+- Cabal flags for controlling whether or not `aeson` and `semigroupoids`
+  are used. These are mostly provided to accelerate builds `primitive`'s 
+  test suite.
+
 ## [0.4.3] - 2018-03-23
 ### Added
 - Property tests for `foldl1` and `foldr1`.
diff --git a/quickcheck-classes.cabal b/quickcheck-classes.cabal
--- a/quickcheck-classes.cabal
+++ b/quickcheck-classes.cabal
@@ -1,5 +1,5 @@
 name: quickcheck-classes
-version: 0.4.3
+version: 0.4.4
 synopsis: QuickCheck common typeclasses
 description:
   This library provides quickcheck properties to
@@ -20,6 +20,23 @@
 cabal-version: >=1.10
 extra-source-files: changelog.md
 
+flag aeson
+  description:
+    You can disable the use of the `aeson` package using `-f-aeson`.
+    .
+    This may be useful for accelerating builds in sandboxes for expert users.
+  default: True
+  manual: True
+
+flag semigroupoids
+  description:
+    You can disable the use of the `semigroupoids` package using `-f-semigroupoids`.
+    .
+    This may be useful for accelerating builds in sandboxes for expert users.
+  default: True
+  manual: True
+
+
 library
   hs-source-dirs: src
   exposed-modules:
@@ -30,11 +47,13 @@
     , QuickCheck >= 2.9
     , transformers >= 0.3 && < 0.6
     , primitive >= 0.6.1 && < 0.7
-    , aeson
     , containers
     , semigroups
     , tagged
-    , semigroupoids 
+  if flag(aeson)
+    build-depends: aeson
+  if flag(semigroupoids)
+    build-depends: semigroupoids 
   default-language: Haskell2010
 
 test-suite test
@@ -46,10 +65,11 @@
     , quickcheck-classes
     , QuickCheck
     , primitive
-    , aeson
     , vector
     , transformers
     , tagged
+  if flag(aeson)
+    build-depends: aeson
   default-language: Haskell2010
 
 source-repository head
diff --git a/src/Test/QuickCheck/Classes.hs b/src/Test/QuickCheck/Classes.hs
--- a/src/Test/QuickCheck/Classes.hs
+++ b/src/Test/QuickCheck/Classes.hs
@@ -42,9 +42,10 @@
   , eqLaws
   , ordLaws
   , showReadLaws
+#if defined(VERSION_aeson)
   , jsonLaws
+#endif
   , integralLaws
-  , jsonLaws
   , monoidLaws
   , ordLaws
   , primLaws
@@ -59,7 +60,9 @@
 #if MIN_VERSION_QuickCheck(2,10,0)
     -- ** Higher-Kinded Types
 #if MIN_VERSION_base(4,9,0) || MIN_VERSION_transformers(0,4,0)
+#if defined(VERSION_semigroupoids)
   , altLaws 
+#endif
   , alternativeLaws 
   , applicativeLaws
   , foldableLaws
@@ -78,7 +81,6 @@
 import Data.Functor ((<$))
 import Control.Applicative (liftA2,(<*>),pure,Applicative,(<$>),Alternative(..))
 import Control.Monad.ST
-import Data.Aeson (FromJSON(..),ToJSON(..))
 import Data.Bifunctor (Bifunctor(..))
 import Data.Bits
 import Data.Foldable (foldMap,Foldable)
@@ -88,7 +90,6 @@
 import Data.Primitive.Addr (Addr(..))
 import Data.Proxy
 import Data.Semigroup (Semigroup)
-import Data.Functor.Alt hiding (Apply)
 import Foreign.Marshal.Alloc
 import Foreign.Marshal.Array
 import Foreign.Storable
@@ -100,13 +101,22 @@
 import Test.QuickCheck.Property (Property(..))
 import Control.Monad.Primitive (PrimMonad,PrimState,primitive,primitive_)
 import qualified Control.Monad.Trans.Writer.Lazy as WL
-import qualified Data.Aeson as AE
 import qualified Data.Primitive as P
 import qualified Data.Semigroup as SG
 import qualified Data.Monoid as MND
 import qualified Data.List as L
 import qualified Data.Set as S
 
+#if defined(VERSION_semigroupoids)
+import Data.Functor.Alt (Alt)
+import qualified Data.Functor.Alt as Alt
+#endif
+
+#if defined(VERSION_aeson)
+import Data.Aeson (FromJSON(..),ToJSON(..))
+import qualified Data.Aeson as AE
+#endif
+
 #if MIN_VERSION_base(4,6,0)
 import Text.Read (readMaybe)
 #endif
@@ -201,12 +211,27 @@
 --
 -- Note that in the second propertiy, the type of decode is @ByteString -> Value@,
 -- not @ByteString -> a@
+#if defined(VERSION_aeson)
 jsonLaws :: (ToJSON a, FromJSON a, Show a, Arbitrary a, Eq a) => Proxy a -> Laws
 jsonLaws p = Laws "ToJSON/FromJSON"
   [ ("Partial Isomorphism", jsonEncodingPartialIsomorphism p)
   , ("Encoding Equals Value", jsonEncodingEqualsValue p)
   ]
 
+-- TODO: improve the quality of the error message if
+-- something does not pass this test.
+jsonEncodingEqualsValue :: forall a. (ToJSON a, Show a, Arbitrary a) => Proxy a -> Property
+jsonEncodingEqualsValue _ = property $ \(a :: a) ->
+  case AE.decode (AE.encode a) of
+    Nothing -> False
+    Just (v :: AE.Value) -> v == toJSON a
+
+jsonEncodingPartialIsomorphism :: forall a. (ToJSON a, FromJSON a, Show a, Eq a, Arbitrary a) => Proxy a -> Property
+jsonEncodingPartialIsomorphism _ = property $ \(a :: a) ->
+  AE.decode (AE.encode a) == Just a
+
+#endif
+
 -- | Tests the following properties:
 --
 -- [/Partial Isomorphism/]
@@ -408,18 +433,6 @@
   read (show a) == a
 #endif
 
--- TODO: improve the quality of the error message if
--- something does not pass this test.
-jsonEncodingEqualsValue :: forall a. (ToJSON a, Show a, Arbitrary a) => Proxy a -> Property
-jsonEncodingEqualsValue _ = property $ \(a :: a) ->
-  case AE.decode (AE.encode a) of
-    Nothing -> False
-    Just (v :: AE.Value) -> v == toJSON a
-
-jsonEncodingPartialIsomorphism :: forall a. (ToJSON a, FromJSON a, Show a, Eq a, Arbitrary a) => Proxy a -> Property
-jsonEncodingPartialIsomorphism _ = property $ \(a :: a) ->
-  AE.decode (AE.encode a) == Just a
-
 eqTransitive :: forall a. (Show a, Eq a, Arbitrary a) => Proxy a -> Property
 eqTransitive _ = property $ \(a :: a) b c -> case a == b of
   True -> case b == c of
@@ -820,12 +833,21 @@
 --   @(a '<!>' b) '<!>' c ≡ a '<!>' (b '<!>' c)@
 -- [/Left Distributivity/]
 --   @f '<$>' (a '<!>' b) = (f '<$>' a) '<!>' (f '<$>' b)
+#if defined(VERSION_semigroupoids)
 altLaws :: (Alt f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Laws
 altLaws p = Laws "Alt"
   [ ("Associativity", altAssociative p)
   , ("Left Distributivity", altLeftDistributive p)
   ]
 
+altAssociative :: forall proxy f. (Alt f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
+altAssociative _ = property $ \(Apply (a :: f Integer)) (Apply (b :: f Integer)) (Apply (c :: f Integer)) -> eq1 ((a Alt.<!> b) Alt.<!> c) (a Alt.<!> (b Alt.<!> c))
+
+altLeftDistributive :: forall proxy f. (Alt f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
+altLeftDistributive _ = property $ \(Apply (a :: f Integer)) (Apply (b :: f Integer)) -> eq1 (id <$> (a Alt.<!> b)) ((id <$> a) Alt.<!> (id <$> b))
+#endif
+
+
 -- | Tests the following monadic properties:
 --
 -- [/Left Identity/]
@@ -1308,12 +1330,6 @@
 functorConst :: forall proxy f. (Functor f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
 functorConst _ = property $ \(Apply (a :: f Integer)) ->
   eq1 (fmap (const 'X') a) ('X' <$ a)
-
-altAssociative :: forall proxy f. (Alt f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
-altAssociative _ = property $ \(Apply (a :: f Integer)) (Apply (b :: f Integer)) (Apply (c :: f Integer)) -> eq1 ((a <!> b) <!> c) (a <!> (b <!> c))
-
-altLeftDistributive :: forall proxy f. (Alt f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
-altLeftDistributive _ = property $ \(Apply (a :: f Integer)) (Apply (b :: f Integer)) -> eq1 (id <$> (a <!> b)) ((id <$> a) <!> (id <$> b))
 
 alternativeIdentity :: forall proxy f. (Alternative f, Eq1 f, Show1 f, Arbitrary1 f) => proxy f -> Property
 alternativeIdentity _ = property $ \(Apply (a :: f Integer)) -> (eq1 (empty <|> a) a) && (eq1 a (empty <|> a))
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -6,7 +6,9 @@
 
 import Control.Monad
 import Control.Applicative
+#if defined(VERSION_aeson)
 import Data.Aeson (ToJSON,FromJSON)
+#endif
 import Data.Bits
 import Data.Foldable
 import Data.Traversable
@@ -57,8 +59,10 @@
   , Arbitrary a
   , Show a
   , Read a
+#if defined(VERSION_aeson)
   , ToJSON a
   , FromJSON a
+#endif
 #if MIN_VERSION_base(4,7,0)
   , FiniteBits a
 #endif
@@ -68,7 +72,9 @@
   , storableLaws p
   , monoidLaws (Proxy :: Proxy (Sum a))
   , showReadLaws p
+#if defined(VERSION_aeson)
   , jsonLaws p
+#endif
   , eqLaws p
   , ordLaws p
   , integralLaws p