diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 2.0.3 (2021-10-30)
+
+- Add instances for `Solo`
+
 # 2.0.2 (2020-02-18)
 
 - Add `Algebra.Lattice.Stacked`
diff --git a/lattices.cabal b/lattices.cabal
--- a/lattices.cabal
+++ b/lattices.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.18
 name:               lattices
-version:            2.0.2
+version:            2.0.3
 category:           Math
 license:            BSD3
 license-file:       LICENSE
@@ -29,7 +29,10 @@
    || ==8.2.2
    || ==8.4.4
    || ==8.6.5
-   || ==8.8.1
+   || ==8.8.3
+   || ==8.10.4
+   || ==9.0.1
+   || ==9.2.1
 
 synopsis:
   Fine-grained library for constructing and manipulating lattices
@@ -79,13 +82,13 @@
     Algebra.PartialOrd.Instances
 
   build-depends:
-      base                        >=4.6      && <4.14
-    , base-compat                 >=0.10.5   && <0.12
+      base                        >=4.6      && <4.17
+    , base-compat                 >=0.10.5   && <0.13
     , containers                  >=0.5.0.0  && <0.7
     , deepseq                     >=1.3.0.0  && <1.5
     , hashable                    >=1.2.7.0  && <1.4
     , integer-logarithms          >=1.0.3    && <1.1
-    , QuickCheck                  >=2.12.6.1 && <2.14
+    , QuickCheck                  >=2.12.6.1 && <2.15
     , semigroupoids               >=5.3.2    && <5.4
     , tagged                      >=0.8.6    && <0.9
     , transformers                >=0.3.0.0  && <0.6
@@ -93,6 +96,12 @@
     , universe-reverse-instances  >=1.1      && <1.2
     , unordered-containers        >=0.2.8.0  && <0.3
 
+  if !impl(ghc >=9.2)
+    if impl(ghc >=9.0)
+      build-depends: ghc-prim
+    else
+      build-depends: OneTuple >=0.3 && <0.4
+
   if !impl(ghc >=8.0)
     build-depends: semigroups >=0.18.5 && <0.20
 
@@ -115,7 +124,7 @@
     , lattices
     , QuickCheck
     , quickcheck-instances        >=0.3.19 && <0.4
-    , tasty                       >=1.2.1  && <1.3
+    , tasty                       >=1.2.1  && <1.5
     , tasty-quickcheck            >=0.10   && <0.11
     , transformers
     , universe-base
diff --git a/src/Algebra/Heyting.hs b/src/Algebra/Heyting.hs
--- a/src/Algebra/Heyting.hs
+++ b/src/Algebra/Heyting.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP             #-}
 {-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE Safe            #-}
 ----------------------------------------------------------------------------
@@ -26,6 +27,14 @@
 import qualified Data.HashSet as HS
 import qualified Data.Set     as Set
 
+#if MIN_VERSION_base(4,16,0)
+import Data.Tuple (Solo (..))
+#elif MIN_VERSION_base(4,15,0)
+import GHC.Tuple (Solo (..))
+#else
+import Data.Tuple.Solo (Solo (..))
+#endif
+
 -- | A Heyting algebra is a bounded lattice equipped with a
 -- binary operation \(a \to b\) of implication.
 --
@@ -101,7 +110,7 @@
     Endo a <=> Endo b = Endo (a <=> b)
 
 -------------------------------------------------------------------------------
--- Proxy, Tagged, Const, Identity
+-- Proxy, Tagged, Const, Identity, Solo
 -------------------------------------------------------------------------------
 
 instance Heyting (Proxy a) where
@@ -123,6 +132,12 @@
     Const a ==> Const b = Const (a ==> b)
     neg (Const a)       = Const (neg a)
     Const a <=> Const b = Const (a <=> b)
+
+-- | @since 2.0.3
+instance Heyting a => Heyting (Solo a) where
+    Solo a ==> Solo b = Solo (a ==> b)
+    neg (Solo a)      = Solo (neg a)
+    Solo a <=> Solo b = Solo (a <=> b)
 
 -------------------------------------------------------------------------------
 -- Sets
diff --git a/src/Algebra/Heyting/Free.hs b/src/Algebra/Heyting/Free.hs
--- a/src/Algebra/Heyting/Free.hs
+++ b/src/Algebra/Heyting/Free.hs
@@ -30,6 +30,11 @@
 import qualified Algebra.Heyting.Free.Expr as E
 import qualified Test.QuickCheck           as QC
 
+-- $setup
+-- >>> import Algebra.Lattice
+-- >>> import Algebra.PartialOrd
+-- >>> import Algebra.Heyting
+
 -------------------------------------------------------------------------------
 -- Free
 -------------------------------------------------------------------------------
diff --git a/src/Algebra/Lattice.hs b/src/Algebra/Lattice.hs
--- a/src/Algebra/Lattice.hs
+++ b/src/Algebra/Lattice.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                #-}
 {-# LANGUAGE ConstraintKinds    #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveGeneric      #-}
@@ -65,6 +66,14 @@
 import qualified Data.Set          as Set
 import qualified Test.QuickCheck   as QC
 
+#if MIN_VERSION_base(4,16,0)
+import Data.Tuple (Solo (..))
+#elif MIN_VERSION_base(4,15,0)
+import GHC.Tuple (Solo (..))
+#else
+import Data.Tuple.Solo (Solo (..))
+#endif
+
 infixr 6 /\ -- This comment needed because of CPP
 infixr 5 \/
 
@@ -81,7 +90,7 @@
 -- x '/\' (y '/\' z) ≡ (x '/\' y) '/\' z
 -- @
 --
--- /Commputativity/
+-- /Commutativity/
 --
 -- @
 -- x '\/' y ≡ y '\/' x
@@ -487,6 +496,23 @@
 
 instance BoundedJoinSemiLattice QC.Property where bottom = QC.property False
 instance BoundedMeetSemiLattice QC.Property where top = QC.property True
+
+-------------------------------------------------------------------------------
+-- OneTuple
+-------------------------------------------------------------------------------
+
+-- | @since 2.0.3
+instance Lattice a => Lattice (Solo a) where
+  Solo a \/ Solo b = Solo (a \/ b)
+  Solo a /\ Solo b = Solo (a /\ b)
+
+-- | @since 2.0.3
+instance BoundedMeetSemiLattice a => BoundedMeetSemiLattice (Solo a) where
+  top = Solo top
+
+-- | @since 2.0.3
+instance BoundedJoinSemiLattice a => BoundedJoinSemiLattice (Solo a) where
+  bottom = Solo bottom
 
 -------------------------------------------------------------------------------
 -- Theorems
diff --git a/src/Algebra/Lattice/Free.hs b/src/Algebra/Lattice/Free.hs
--- a/src/Algebra/Lattice/Free.hs
+++ b/src/Algebra/Lattice/Free.hs
@@ -29,6 +29,9 @@
 import qualified Algebra.Heyting.Free.Expr as E
 import qualified Test.QuickCheck           as QC
 
+-- $setup
+-- >>> import Algebra.Lattice
+
 -------------------------------------------------------------------------------
 -- Free
 -------------------------------------------------------------------------------
diff --git a/test/Tests.hs b/test/Tests.hs
--- a/test/Tests.hs
+++ b/test/Tests.hs
@@ -181,6 +181,7 @@
     apProp :: m (Fun Int Int) -> m Int -> Property
     apProp f x = (f' <*> x) === ap f' x
        where f' = apply <$> f
+{-# NOINLINE monadLaws #-}
 
 -------------------------------------------------------------------------------
 -- Partial ord laws
@@ -235,6 +236,7 @@
         agree True False = (=== LT)
         agree False True = (=== GT)
         agree False False = discard
+{-# NOINLINE partialOrdLaws #-}
 
 -------------------------------------------------------------------------------
 -- Lattice
@@ -292,6 +294,7 @@
         [ booleanLaws pr | b >= IsBoolean ]
   where
     name = show (typeOf (undefined :: a))
+{-# NOINLINE allLatticeLaws #-}
 
 allLatticeLaws'
     :: forall a. (Eq a, Show a, Arbitrary a, Lattice a, PartialOrd a)
@@ -369,6 +372,7 @@
 
     comparableDef :: a -> a -> Property
     comparableDef x y = (leq x y || leq y x) === comparable x y
+{-# NOINLINE latticeLaws #-}
 
 -------------------------------------------------------------------------------
 -- Modular
@@ -386,6 +390,7 @@
     modularProp x y z = lhs === rhs where
         lhs = (y /\ (x \/ z)) \/ z
         rhs = (y \/ z) /\ (x \/ z)
+{-# NOINLINE modularLaws #-}
 
 -------------------------------------------------------------------------------
 -- Distributive
@@ -409,6 +414,7 @@
     distr2Prop x y z = lhs === rhs where
         lhs = x \/ (y /\ z)
         rhs = (x \/ y) /\ (x \/ z)
+{-# NOINLINE distributiveLaws #-}
 
 -------------------------------------------------------------------------------
 -- Bounded lattice laws
@@ -444,6 +450,7 @@
     annihilationRightProp x = lhs === rhs where
         lhs = x \/ top
         rhs = top
+{-# NOINLINE boundedMeetLaws #-}
 
 boundedJoinLaws
     :: forall a. (Eq a, Show a, Arbitrary a, BoundedJoinSemiLattice a)
@@ -475,6 +482,7 @@
     annihilationRightProp x = lhs === rhs where
         lhs = x /\ bottom
         rhs = bottom
+{-# NOINLINE boundedJoinLaws #-}
 
 -------------------------------------------------------------------------------
 -- Heyting laws
@@ -541,6 +549,7 @@
     deMorganProp2weak x y = lhs === rhs where
         lhs = neg (x /\ y)
         rhs = neg (neg (neg x \/ neg y))
+{-# NOINLINE heytingLaws #-}
 
 -------------------------------------------------------------------------------
 -- De morgan
@@ -558,6 +567,7 @@
     deMorganProp2 x y = lhs === rhs where
         lhs = neg (x /\ y)
         rhs = neg x \/ neg y
+{-# NOINLINE deMorganLaws #-}
 
 -------------------------------------------------------------------------------
 -- Boolean laws
@@ -584,6 +594,7 @@
     dnProp x = lhs === rhs where
         lhs = neg (neg x)
         rhs = x
+{-# NOINLINE booleanLaws #-}
 
 -------------------------------------------------------------------------------
 -- Universe / Finite laws
@@ -620,6 +631,7 @@
 
     cardinalityProp :: Property
     cardinalityProp = cardinality === (Tagged (genericLength (universeF :: [a])) :: Tagged a Natural)
+{-# NOINLINE finiteLaws #-}
 
 -------------------------------------------------------------------------------
 -- Lexicographic M2 search