diff --git a/arithmoi.cabal b/arithmoi.cabal
--- a/arithmoi.cabal
+++ b/arithmoi.cabal
@@ -1,5 +1,5 @@
 name:          arithmoi
-version:       0.11.0.0
+version:       0.11.0.1
 cabal-version: >=1.10
 build-type:    Simple
 license:       MIT
@@ -39,7 +39,7 @@
     integer-logarithms >=1.0,
     integer-roots >=1.0,
     mod,
-    random >=1.0 && <1.2,
+    random >=1.0 && <1.3,
     transformers >=0.4 && <0.6,
     semirings >=0.5.2,
     vector >=0.12
@@ -124,7 +124,7 @@
     QuickCheck >=2.10,
     quickcheck-classes >=0.6.3,
     semirings >=0.2,
-    smallcheck >=1.1.3 && <1.2,
+    smallcheck >=1.2 && <1.3,
     tasty >=0.10,
     tasty-hunit >=0.9 && <0.11,
     tasty-quickcheck >=0.9 && <0.11,
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 0.11.0.1
+
+### Changed
+
+* Switch to `smallcheck-1.2.0`.
+
 ## 0.11.0.0
 
 ### Added
diff --git a/test-suite/Math/NumberTheory/CurvesTests.hs b/test-suite/Math/NumberTheory/CurvesTests.hs
--- a/test-suite/Math/NumberTheory/CurvesTests.hs
+++ b/test-suite/Math/NumberTheory/CurvesTests.hs
@@ -14,7 +14,7 @@
 module Math.NumberTheory.CurvesTests where
 
 import Test.Tasty
-import Test.Tasty.QuickCheck as QC hiding (Positive, NonNegative, generate, getNonNegative)
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonNegative(..))
 
 import GHC.TypeNats (KnownNat)
 
diff --git a/test-suite/Math/NumberTheory/EisensteinIntegersTests.hs b/test-suite/Math/NumberTheory/EisensteinIntegersTests.hs
--- a/test-suite/Math/NumberTheory/EisensteinIntegersTests.hs
+++ b/test-suite/Math/NumberTheory/EisensteinIntegersTests.hs
@@ -17,7 +17,7 @@
 import Data.Euclidean
 import Data.Maybe (fromJust, isJust)
 import Data.Proxy
-import Test.Tasty.QuickCheck as QC hiding (Positive, getPositive, NonNegative, generate, getNonNegative)
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonNegative(..))
 import Test.QuickCheck.Classes
 import Test.Tasty                                     (TestTree, testGroup)
 import Test.Tasty.HUnit                               (Assertion, assertEqual,
diff --git a/test-suite/Math/NumberTheory/EuclideanTests.hs b/test-suite/Math/NumberTheory/EuclideanTests.hs
--- a/test-suite/Math/NumberTheory/EuclideanTests.hs
+++ b/test-suite/Math/NumberTheory/EuclideanTests.hs
@@ -21,7 +21,7 @@
 import Prelude hiding (gcd)
 import Test.Tasty
 import Test.Tasty.HUnit
-import Test.Tasty.QuickCheck as QC hiding (Positive(..))
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonZero(..))
 
 import Control.Arrow
 import Data.Bits
diff --git a/test-suite/Math/NumberTheory/GaussianIntegersTests.hs b/test-suite/Math/NumberTheory/GaussianIntegersTests.hs
--- a/test-suite/Math/NumberTheory/GaussianIntegersTests.hs
+++ b/test-suite/Math/NumberTheory/GaussianIntegersTests.hs
@@ -19,7 +19,7 @@
 import Data.List (groupBy, sort)
 import Data.Maybe (fromJust, mapMaybe)
 import Data.Proxy
-import Test.Tasty.QuickCheck as QC hiding (Positive, getPositive, NonNegative, generate, getNonNegative)
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonNegative(..))
 import Test.QuickCheck.Classes
 import Test.Tasty
 import Test.Tasty.HUnit
diff --git a/test-suite/Math/NumberTheory/TestUtils.hs b/test-suite/Math/NumberTheory/TestUtils.hs
--- a/test-suite/Math/NumberTheory/TestUtils.hs
+++ b/test-suite/Math/NumberTheory/TestUtils.hs
@@ -49,11 +49,11 @@
   ) where
 
 import Test.QuickCheck.Classes
-import Test.SmallCheck.Series (Positive(..), NonNegative(..), Serial(..), Series, generate, (\/), cons2)
+import Test.SmallCheck.Series (Positive(..), NonNegative(..), NonZero(..), Serial(..), Series, generate, (\/), cons2)
 import Test.Tasty
 import Test.Tasty.HUnit       (Assertion, assertBool)
 import Test.Tasty.SmallCheck as SC
-import Test.Tasty.QuickCheck as QC hiding (Positive, getPositive, NonNegative, generate, getNonNegative)
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonNegative(..), NonZero(..), generate)
 
 import Data.Bits
 import Data.Euclidean
diff --git a/test-suite/Math/NumberTheory/TestUtils/Wrappers.hs b/test-suite/Math/NumberTheory/TestUtils/Wrappers.hs
--- a/test-suite/Math/NumberTheory/TestUtils/Wrappers.hs
+++ b/test-suite/Math/NumberTheory/TestUtils/Wrappers.hs
@@ -31,8 +31,8 @@
 import Data.Functor.Classes
 import Data.Semiring (Semiring)
 
-import Test.Tasty.QuickCheck as QC hiding (Positive, NonNegative, generate, getNonNegative, getPositive)
-import Test.SmallCheck.Series (Positive(..), NonNegative(..), Serial(..), Series)
+import Test.Tasty.QuickCheck as QC hiding (Positive(..), NonNegative(..), NonZero(..))
+import Test.SmallCheck.Series (Positive(..), NonNegative(..), NonZero(..), Serial(..), Series)
 
 import Math.NumberTheory.Primes (Prime, UniqueFactorisation(..))
 
@@ -57,7 +57,6 @@
 -------------------------------------------------------------------------------
 -- Positive from smallcheck
 
-deriving instance Functor Positive
 deriving instance Semiring a => Semiring (Positive a)
 deriving instance GcdDomain a => GcdDomain (Positive a)
 deriving instance Euclidean a => Euclidean (Positive a)
@@ -66,10 +65,6 @@
   arbitrary = Positive <$> (arbitrary `suchThat` (> 0))
   shrink (Positive x) = Positive <$> filter (> 0) (shrink x)
 
-instance (Num a, Bounded a) => Bounded (Positive a) where
-  minBound = Positive 1
-  maxBound = Positive (maxBound :: a)
-
 instance Eq1 Positive where
   liftEq eq (Positive a) (Positive b) = a `eq` b
 
@@ -82,7 +77,6 @@
 -------------------------------------------------------------------------------
 -- NonNegative from smallcheck
 
-deriving instance Functor NonNegative
 deriving instance Semiring a => Semiring (NonNegative a)
 deriving instance GcdDomain a => GcdDomain (NonNegative a)
 deriving instance Euclidean a => Euclidean (NonNegative a)
@@ -91,10 +85,6 @@
   arbitrary = NonNegative <$> (arbitrary `suchThat` (>= 0))
   shrink (NonNegative x) = NonNegative <$> filter (>= 0) (shrink x)
 
-instance (Num a, Bounded a) => Bounded (NonNegative a) where
-  minBound = NonNegative 0
-  maxBound = NonNegative (maxBound :: a)
-
 instance Eq1 NonNegative where
   liftEq eq (NonNegative a) (NonNegative b) = a `eq` b
 
@@ -105,14 +95,24 @@
   liftShowsPrec shw _ p (NonNegative a) = shw p a
 
 -------------------------------------------------------------------------------
--- NonZero from QuickCheck
+-- NonZero from smallcheck
 
-instance (Monad m, Num a, Eq a, Serial m a) => Serial m (NonZero a) where
-  series = NonZero <$> series `suchThatSerial` (/= 0)
+deriving instance Semiring a => Semiring (NonZero a)
+deriving instance GcdDomain a => GcdDomain (NonZero a)
+deriving instance Euclidean a => Euclidean (NonZero a)
 
-instance (Eq a, Num a, Enum a, Bounded a) => Bounded (NonZero a) where
-  minBound = if minBound == (0 :: a) then NonZero (succ minBound) else NonZero minBound
-  maxBound = if maxBound == (0 :: a) then NonZero (pred maxBound) else NonZero maxBound
+instance (Num a, Ord a, Arbitrary a) => Arbitrary (NonZero a) where
+  arbitrary = NonZero <$> (arbitrary `suchThat` (/= 0))
+  shrink (NonZero x) = NonZero <$> filter (/= 0) (shrink x)
+
+instance Eq1 NonZero where
+  liftEq eq (NonZero a) (NonZero b) = a `eq` b
+
+instance Ord1 NonZero where
+  liftCompare cmp (NonZero a) (NonZero b) = a `cmp` b
+
+instance Show1 NonZero where
+  liftShowsPrec shw _ p (NonZero a) = shw p a
 
 -------------------------------------------------------------------------------
 -- Huge