diff --git a/.travis.yml b/.travis.yml
index 0b696e7..e563175 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -81,7 +81,7 @@ script:
  - if [ -f configure.ac ]; then autoreconf -i; fi
  - cabal configure --enable-tests --enable-benchmarks -v2  # -v2 provides useful information for debugging
  - cabal build   # this builds all libraries and executables (including tests/benchmarks)
- - cabal test
+ - cabal test --flag quickcheck
  - cabal check
  - cabal sdist   # tests that a source-distribution can be generated
 
diff --git a/include/thyme.h b/include/thyme.h
index ee4449c..db25029 100644
--- a/include/thyme.h
+++ b/include/thyme.h
@@ -1,6 +1,10 @@
 #define INSTANCES_USUAL     Eq, Ord, Data, Typeable, Generic
 #define INSTANCES_NEWTYPE   INSTANCES_USUAL, Enum, Ix, Hashable, NFData
+#ifdef QUICKCHECK
 #define INSTANCES_MICRO     INSTANCES_NEWTYPE, Bounded, Random, Arbitrary, CoArbitrary
+#else
+#define INSTANCES_MICRO     INSTANCES_NEWTYPE, Bounded, Random
+#endif
 #define LensP Lens'
 #define LENS(S,F,A) {-# INLINE _/**/F #-}; _/**/F :: LensP S A; _/**/F = lens F $ \ S {..} F/**/_ -> S {F = F/**/_, ..}
 
diff --git a/src/Data/Thyme/Calendar.hs b/src/Data/Thyme/Calendar.hs
index 5d4793a..319e121 100644
--- a/src/Data/Thyme/Calendar.hs
+++ b/src/Data/Thyme/Calendar.hs
@@ -38,13 +38,15 @@ import Control.Applicative
 import Control.Arrow
 import Control.Category
 import Control.Lens
-import Control.Monad
 import Data.AdditiveGroup
 import Data.AffineSpace
 import Data.Thyme.Calendar.Internal
 import Data.Thyme.Clock.Internal
 import System.Random
+#ifdef QUICKCHECK
+import Control.Monad
 import Test.QuickCheck
+#endif
 
 -- "Data.Thyme.Calendar.Internal" cannot import "Data.Thyme.Clock.Internal",
 -- therefore these orphan 'Bounded' instances must live here.
@@ -67,6 +69,7 @@ instance Random YearMonthDay where
     randomR = randomIsoR gregorian
     random = first (^. gregorian) . random
 
+#ifdef QUICKCHECK
 instance Arbitrary Day where
     arbitrary = ModifiedJulianDay
         <$> choose (join (***) toModifiedJulianDay (minBound, maxBound))
@@ -79,6 +82,7 @@ instance Arbitrary YearMonthDay where
 instance CoArbitrary YearMonthDay where
     coarbitrary (YearMonthDay y m d)
         = coarbitrary y . coarbitrary m . coarbitrary d
+#endif
 
 ------------------------------------------------------------------------
 
diff --git a/src/Data/Thyme/Calendar/Internal.hs b/src/Data/Thyme/Calendar/Internal.hs
index 3a9f60b..002d1b2 100644
--- a/src/Data/Thyme/Calendar/Internal.hs
+++ b/src/Data/Thyme/Calendar/Internal.hs
@@ -43,7 +43,9 @@ import qualified Data.Vector.Unboxed as VU
 import Data.Vector.Unboxed.Deriving
 import GHC.Generics (Generic)
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck hiding ((.&.))
+#endif
 
 -- | A duration/count of years.
 type Years = Int
@@ -82,9 +84,15 @@ type Days = Int
 -- @
 --
 -- Other ways of viewing a 'Day' include 'ordinalDate', and 'weekDate'.
+#ifdef QUICKCHECK
 newtype Day = ModifiedJulianDay
     { toModifiedJulianDay :: Int
     } deriving (INSTANCES_NEWTYPE, CoArbitrary)
+#else
+newtype Day = ModifiedJulianDay
+    { toModifiedJulianDay :: Int
+    } deriving (INSTANCES_NEWTYPE)
+#endif
 
 instance AffineSpace Day where
     type Diff Day = Days
@@ -385,12 +393,14 @@ instance Random MonthDay where
         (isLeapYear -> leap, g') = random g
     random = randomR (minBound, maxBound)
 
+#ifdef QUICKCHECK
 instance Arbitrary MonthDay where
     arbitrary = choose (minBound, maxBound)
     shrink md = view (monthDay True) <$> shrink (monthDay True # md)
 
 instance CoArbitrary MonthDay where
     coarbitrary (MonthDay m d) = coarbitrary m . coarbitrary d
+#endif
 
 -- | Predicated on whether or not it's a leap year, convert between an
 -- ordinal 'DayOfYear' and the corresponding 'Month' and 'DayOfMonth'.
diff --git a/src/Data/Thyme/Calendar/OrdinalDate.hs b/src/Data/Thyme/Calendar/OrdinalDate.hs
index e467d6e..9d1c37a 100644
--- a/src/Data/Thyme/Calendar/OrdinalDate.hs
+++ b/src/Data/Thyme/Calendar/OrdinalDate.hs
@@ -27,7 +27,9 @@ import Control.Monad
 import Data.Thyme.Calendar
 import Data.Thyme.Calendar.Internal
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck
+#endif
 
 instance Bounded OrdinalDate where
     minBound = minBound ^. ordinalDate
@@ -37,12 +39,14 @@ instance Random OrdinalDate where
     randomR = randomIsoR ordinalDate
     random = first (^. ordinalDate) . random
 
+#ifdef QUICKCHECK
 instance Arbitrary OrdinalDate where
     arbitrary = view ordinalDate <$> arbitrary
     shrink od = view ordinalDate <$> shrink (ordinalDate # od)
 
 instance CoArbitrary OrdinalDate where
     coarbitrary (OrdinalDate y d) = coarbitrary y . coarbitrary d
+#endif
 
 -- | Convert an 'OrdinalDate' to a 'Day', or 'Nothing' for invalid input.
 --
diff --git a/src/Data/Thyme/Calendar/WeekDate.hs b/src/Data/Thyme/Calendar/WeekDate.hs
index fcc8ea1..044c77c 100644
--- a/src/Data/Thyme/Calendar/WeekDate.hs
+++ b/src/Data/Thyme/Calendar/WeekDate.hs
@@ -38,7 +38,9 @@ import Control.Lens
 import Data.Thyme.Calendar.OrdinalDate
 import Data.Thyme.Calendar.Internal
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck
+#endif
 
 instance Bounded WeekDate where
     minBound = minBound ^. weekDate
@@ -64,6 +66,7 @@ instance Random MondayWeek where
     randomR = randomIsoR mondayWeek
     random = first (^. mondayWeek) . random
 
+#ifdef QUICKCHECK
 instance Arbitrary WeekDate where
     arbitrary = view weekDate <$> arbitrary
     shrink wd = view weekDate <$> shrink (weekDate # wd)
@@ -87,6 +90,7 @@ instance CoArbitrary SundayWeek where
 instance CoArbitrary MondayWeek where
     coarbitrary (MondayWeek y w d)
         = coarbitrary y . coarbitrary w . coarbitrary d
+#endif
 
 -- * Compatibility
 
diff --git a/src/Data/Thyme/Calendar/WeekdayOfMonth.hs b/src/Data/Thyme/Calendar/WeekdayOfMonth.hs
index 0c56ffa..6bf8e7a 100644
--- a/src/Data/Thyme/Calendar/WeekdayOfMonth.hs
+++ b/src/Data/Thyme/Calendar/WeekdayOfMonth.hs
@@ -39,7 +39,9 @@ import qualified Data.Vector.Generic.Mutable
 import Data.Vector.Unboxed.Deriving
 import GHC.Generics (Generic)
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck hiding ((.&.))
+#endif
 
 -- | Calendar date with year, month-of-year, and n-th day-of-week.
 data WeekdayOfMonth = WeekdayOfMonth
@@ -77,6 +79,7 @@ instance Random WeekdayOfMonth where
     randomR = randomIsoR weekdayOfMonth
     random = first (^. weekdayOfMonth) . random
 
+#ifdef QUICKCHECK
 instance Arbitrary WeekdayOfMonth where
     arbitrary = view weekdayOfMonth <$> arbitrary
     shrink wom = view weekdayOfMonth <$> shrink (weekdayOfMonth # wom)
@@ -85,6 +88,7 @@ instance CoArbitrary WeekdayOfMonth where
     coarbitrary (WeekdayOfMonth y m n d)
         = coarbitrary y . coarbitrary m
         . coarbitrary n . coarbitrary d
+#endif
 
 -- | Conversion between a 'Day' and and 'WeekdayOfMonth'.
 --
diff --git a/src/Data/Thyme/Clock/Internal.hs b/src/Data/Thyme/Clock/Internal.hs
index 82dd339..1c97742 100644
--- a/src/Data/Thyme/Clock/Internal.hs
+++ b/src/Data/Thyme/Clock/Internal.hs
@@ -38,7 +38,9 @@ import Data.Vector.Unboxed.Deriving
 import Data.VectorSpace
 import GHC.Generics (Generic)
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck
+#endif
 
 #if !SHOW_INTERNAL
 import Control.Monad
diff --git a/src/Data/Thyme/Clock/TAI.hs b/src/Data/Thyme/Clock/TAI.hs
index 336d81d..06041de 100644
--- a/src/Data/Thyme/Clock/TAI.hs
+++ b/src/Data/Thyme/Clock/TAI.hs
@@ -66,7 +66,9 @@ import Data.Vector.Unboxed.Deriving
 import Data.VectorSpace
 import GHC.Generics (Generic)
 import System.Random (Random)
+#ifdef QUICKCHECK
 import Test.QuickCheck
+#endif
 
 -- | <https://en.wikipedia.org/wiki/International_Atomic_Time Temps Atomique International>
 -- (TAI). Note that for most applications 'UTCTime' is perfectly sufficient,
diff --git a/src/Data/Thyme/Internal/Micro.hs b/src/Data/Thyme/Internal/Micro.hs
index 611a16f..b092db6 100644
--- a/src/Data/Thyme/Internal/Micro.hs
+++ b/src/Data/Thyme/Internal/Micro.hs
@@ -29,7 +29,9 @@ import Data.Vector.Unboxed.Deriving
 import Data.VectorSpace
 import GHC.Generics (Generic)
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck
+#endif
 
 #if !SHOW_INTERNAL
 import Control.Monad
diff --git a/src/Data/Thyme/LocalTime.hs b/src/Data/Thyme/LocalTime.hs
index 941b902..cc6cdc8 100644
--- a/src/Data/Thyme/LocalTime.hs
+++ b/src/Data/Thyme/LocalTime.hs
@@ -50,7 +50,9 @@ import Data.Vector.Unboxed.Deriving
 import Data.VectorSpace
 import GHC.Generics (Generic)
 import System.Random
+#ifdef QUICKCHECK
 import Test.QuickCheck hiding ((.&.))
+#endif
 
 -- | Hours duration.
 type Hours = Int
@@ -102,6 +104,7 @@ instance Random TimeZone where
         randChar nR (ns, g) = (: ns) `first` randomR nR g
     random = randomR (minBound, maxBound)
 
+#ifdef QUICKCHECK
 instance Arbitrary TimeZone where
     arbitrary = choose (minBound, maxBound)
     shrink tz@TimeZone {..}
@@ -112,6 +115,7 @@ instance Arbitrary TimeZone where
 instance CoArbitrary TimeZone where
     coarbitrary (TimeZone m s n)
         = coarbitrary m . coarbitrary s . coarbitrary n
+#endif
 
 -- | Text representing the offset of this timezone, e.g. \"-0800\" or
 -- \"+0400\" (like @%z@ in 'Data.Thyme.Format.formatTime')
@@ -218,6 +222,7 @@ instance Random TimeOfDay where
     randomR = randomIsoR timeOfDay
     random = first (^. timeOfDay) . random
 
+#ifdef QUICKCHECK
 instance Arbitrary TimeOfDay where
     arbitrary = do
         h <- choose (0, 23)
@@ -231,6 +236,7 @@ instance Arbitrary TimeOfDay where
 instance CoArbitrary TimeOfDay where
     coarbitrary (TimeOfDay h m s)
         = coarbitrary h . coarbitrary m . coarbitrary s
+#endif
 
 -- | The maximum possible length of a minute. Always /60s/, except at
 -- /23:59/ due to leap seconds.
@@ -380,6 +386,7 @@ instance Random LocalTime where
     randomR = randomIsoR (utcLocalTime utc)
     random = randomR (minBound, maxBound)
 
+#ifdef QUICKCHECK
 instance Arbitrary LocalTime where
     arbitrary = choose (minBound, maxBound)
     shrink lt@LocalTime {..}
@@ -388,6 +395,7 @@ instance Arbitrary LocalTime where
 
 instance CoArbitrary LocalTime where
     coarbitrary (LocalTime d t) = coarbitrary d . coarbitrary t
+#endif
 
 -- | Conversion between 'UTCTime' and 'LocalTime'.
 --
@@ -482,6 +490,7 @@ instance Random ZonedTime where
         u' = snd $ zonedTime # u
     random = randomR (minBound, maxBound)
 
+#ifdef QUICKCHECK
 instance Arbitrary ZonedTime where
     arbitrary = choose (minBound, maxBound)
     shrink zt@ZonedTime {..}
@@ -490,6 +499,7 @@ instance Arbitrary ZonedTime where
 
 instance CoArbitrary ZonedTime where
     coarbitrary (ZonedTime lt tz) = coarbitrary lt . coarbitrary tz
+#endif
 
 -- | Conversion between ('TimeZone', 'UTCTime') and 'ZonedTime'.
 --
diff --git a/thyme.cabal b/thyme.cabal
index 893de5f..5c9df7b 100644
--- a/thyme.cabal
+++ b/thyme.cabal
@@ -53,6 +53,11 @@ flag show-internal
     default: False
     manual: True
 
+flag quickcheck
+    description: whether to compile quickcheck things
+    default: False
+    manual: True
+
 library
     default-language: Haskell2010
     include-dirs: include
@@ -84,7 +89,6 @@ library
     if !(flag(lens) || flag(docs))
         other-modules: Control.Lens
     build-depends:
-        QuickCheck >= 2.4,
         attoparsec >= 0.10,
         aeson >= 0.6,
         base >= 4.5 && < 5,
@@ -117,6 +121,9 @@ library
         cpp-options: -DBUG_FOR_BUG=1
     if flag(show-internal)
         cpp-options: -DSHOW_INTERNAL=1
+    if flag(quickcheck)
+        build-depends: QuickCheck >= 2.4
+        cpp-options: -DQUICKCHECK=1
 
 test-suite sanity
     default-language: Haskell2010