diff --git a/WORKSPACE b/WORKSPACE
index b75ec7f43c..498c2140d5 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -102,7 +102,6 @@ stack_snapshot(
         "hspec",
         "hspec-core",
         "hspec-expectations",
-        "leancheck",
         "lens",
         "network",
         "network-uri",
diff --git a/semantic/BUILD.bazel b/semantic/BUILD.bazel
index fae0d08468..a3eb0f1114 100644
--- a/semantic/BUILD.bazel
+++ b/semantic/BUILD.bazel
@@ -169,7 +169,6 @@ haskell_test(
         "@stackage//:hspec",
         "@stackage//:hspec-core",
         "@stackage//:hspec-expectations",
-        "@stackage//:leancheck",
         "@stackage//:tasty",
         "@stackage//:tasty-golden",
         "@stackage//:tasty-hedgehog",
diff --git a/semantic/semantic.cabal b/semantic/semantic.cabal
index 83822e2eb9..f1c6841eaa 100644
--- a/semantic/semantic.cabal
+++ b/semantic/semantic.cabal
@@ -198,8 +198,7 @@ test-suite test
   type:                exitcode-stdio-1.0
   hs-source-dirs:      test
   main-is:             Spec.hs
-  other-modules:       Data.Functor.Listable
-                     , Data.Graph.Spec
+  other-modules:       Data.Graph.Spec
                      , Data.Language.Spec
                      , Data.Semigroup.App.Spec
                      , Integration.Spec
@@ -209,7 +208,6 @@ test-suite test
                      , Semantic.Stat.Spec
                      , Tags.Spec
                      , SpecHelpers
-                     , Test.Hspec.LeanCheck
                      , Generators
                      , Properties
   build-depends:       semantic
@@ -228,7 +226,6 @@ test-suite test
                      , tasty-hspec ^>= 1.1.5.1
                      , tasty-hunit ^>= 0.10.0.2
                      , HUnit ^>= 1.6.0.0
-                     , leancheck >= 0.8 && <1
                      , temporary ^>= 1.3
 
 test-suite parse-examples
diff --git a/semantic/test/Data/Functor/Listable.hs b/semantic/test/Data/Functor/Listable.hs
deleted file mode 100644
index 5250a0b2a0..0000000000
--- a/semantic/test/Data/Functor/Listable.hs
+++ /dev/null
@@ -1,112 +0,0 @@
-{-# LANGUAGE DataKinds, FlexibleContexts, FlexibleInstances, ScopedTypeVariables, TypeOperators #-}
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-module Data.Functor.Listable
-( Listable(..)
-, mapT
-, cons0
-, cons1
-, cons2
-, cons3
-, cons4
-, cons5
-, cons6
-, (\/)
-, addWeight
-, ofWeight
-) where
-
-import qualified Analysis.Name as Name
-import Data.Bifunctor.Join
-import Data.Edit
-import qualified Data.Language as Language
-import Data.List.NonEmpty
-import Data.Text as T (Text, pack)
-import Source.Loc
-import Source.Span
-import Test.LeanCheck
-
-type Tier a = [a]
-
--- | Lifting of 'Listable' to @* -> *@.
-class Listable1 l where
-  -- | The tiers for @l :: * -> *@, parameterized by the tiers for @a :: *@.
-  liftTiers :: [Tier a] -> [Tier (l a)]
-
--- | Lifting of 'Listable' to @* -> * -> *@.
-class Listable2 l where
-  -- | The tiers for @l :: * -> * -> *@, parameterized by the tiers for @a :: *@ & @b :: *@.
-  liftTiers2 :: [Tier a] -> [Tier b] -> [Tier (l a b)]
-
--- | A suitable definition of 'tiers' for 'Listable2' type constructors parameterized by 'Listable' types.
-tiers2 :: (Listable a, Listable b, Listable2 l) => [Tier (l a b)]
-tiers2 = liftTiers2 tiers tiers
-
-
--- | Lifts a unary constructor to a list of tiers, given a list of tiers for its argument.
---
---   Commonly used in the definition of 'Listable1' and 'Listable2' instances.
-liftCons1 :: [Tier a] -> (a -> b) -> [Tier b]
-liftCons1 tiers f = mapT f tiers `addWeight` 1
-
--- | Lifts a binary constructor to a list of tiers, given lists of tiers for its arguments.
---
---   Commonly used in the definition of 'Listable1' and 'Listable2' instances.
-liftCons2 :: [Tier a] -> [Tier b] -> (a -> b -> c) -> [Tier c]
-liftCons2 tiers1 tiers2 f = mapT (uncurry f) (liftTiers2 tiers1 tiers2) `addWeight` 1
-
--- Instances
-
-instance Listable1 Maybe where
-  liftTiers tiers = cons0 Nothing \/ liftCons1 tiers Just
-
-instance Listable2 (,) where
-  liftTiers2 = (><)
-
-instance Listable2 Either where
-  liftTiers2 leftTiers rightTiers = liftCons1 leftTiers Left \/ liftCons1 rightTiers Right
-
-instance Listable a => Listable1 ((,) a) where
-  liftTiers = liftTiers2 tiers
-
-instance Listable1 [] where
-  liftTiers tiers = go
-    where go = cons0 [] \/ liftCons2 tiers go (:)
-
-instance Listable1 NonEmpty where
-  liftTiers tiers = liftCons2 tiers (liftTiers tiers) (:|)
-
-instance Listable2 p => Listable1 (Join p) where
-  liftTiers tiers = liftCons1 (liftTiers2 tiers tiers) Join
-
-instance Listable2 Edit where
-  liftTiers2 t1 t2 = liftCons1 t2 Insert \/ liftCons1 t1 Delete \/ liftCons2 t1 t2 Compare
-
-instance (Listable a, Listable b) => Listable (Edit a b) where
-  tiers = tiers2
-
-
-instance Listable Name.Name where
-  tiers = cons1 Name.name
-
-instance Listable Text where
-  tiers = pack `mapT` tiers
-
-instance Listable Language.Language where
-  tiers
-    =  cons0 Language.Go
-    \/ cons0 Language.JavaScript
-    \/ cons0 Language.Python
-    \/ cons0 Language.Ruby
-    \/ cons0 Language.TypeScript
-
-instance Listable Loc where
-  tiers = cons2 Loc
-
-instance Listable Range where
-  tiers = cons2 Range
-
-instance Listable Pos where
-  tiers = cons2 Pos
-
-instance Listable Span where
-  tiers = cons2 Span
diff --git a/semantic/test/SpecHelpers.hs b/semantic/test/SpecHelpers.hs
index 545e857589..7234f33378 100644
--- a/semantic/test/SpecHelpers.hs
+++ b/semantic/test/SpecHelpers.hs
@@ -32,7 +32,6 @@ import           Data.ByteString.Builder (Builder, toLazyByteString)
 import           Data.ByteString.Lazy (toStrict)
 import           Data.Edit as X
 import           Data.Foldable (toList)
-import           Data.Functor.Listable as X
 import           Data.Language as X hiding (Precise)
 import           Data.List.NonEmpty as X (NonEmpty (..))
 import           Data.Maybe as X
@@ -56,8 +55,6 @@ import           System.Exit (die)
 import qualified System.Path as Path
 import           Test.Hspec as X (Spec, SpecWith, around, context, describe, it, parallel, pendingWith, runIO, xit)
 import           Test.Hspec.Expectations as X
-import           Test.Hspec.LeanCheck as X
-import           Test.LeanCheck as X
 
 instance Lower X.Span where
   lowerBound = Source.Span.point (Pos 1 1)
diff --git a/semantic/test/Test/Hspec/LeanCheck.hs b/semantic/test/Test/Hspec/LeanCheck.hs
deleted file mode 100644
index d9e1f52844..0000000000
--- a/semantic/test/Test/Hspec/LeanCheck.hs
+++ /dev/null
@@ -1,93 +0,0 @@
-{-# LANGUAGE FlexibleInstances, GADTs, TypeFamilies #-}
-module Test.Hspec.LeanCheck
-( prop
-, forAll
-) where
-
-import Control.Exception
-import Data.Bifunctor (first)
-import Data.List (intercalate)
-import Data.Maybe (listToMaybe)
-import Test.Hspec
-import Test.Hspec.Core.Spec as Hspec
-import qualified Test.HUnit.Lang as HUnit
-import Test.LeanCheck.Core
-
-data Property where
-  Property :: IOTestable prop => prop -> Property
-
--- | Perform an enumerative test of a property using LeanCheck.
---
---   'prop' will typically be a function of one or more 'Listable' arguments, returning either 'Bool' or 'IO ()' (in the latter case, typically via 'shouldBe' and friends). For example:
---
--- > describe "+" $ do
--- >   prop "associativity" $
--- >     \ a b c -> a + (b + c) `shouldBe` (a + b :: Int) + c
-prop :: (HasCallStack, IOTestable prop) => String -> prop -> Spec
-prop s = it s . Property
-
-data ForAll a where
-  ForAll :: IOTestable prop => [[a]] -> (a -> prop) -> ForAll a
-
--- | Test a property given by an explicit list of tiers rather than a 'Listable' instance. This can be used to e.g. filter input values for which the property does not hold.
---
--- > describe "mean" $ do
--- >   prop "≥ the minimum" . forAll (not . null `filterT` tiers) $
--- >     \ list -> (mean list :: Int) `shouldSatisfy` (>= min list)
-forAll :: IOTestable prop => [[a]] -> (a -> prop) -> ForAll a
-forAll = ForAll
-
-instance Example Property where
-  type Arg Property = ()
-  evaluateExample (Property prop) (Params _ bound) _ _ = do
-    result <- try (iocounterExample bound prop)
-    case result of
-      Left e
-        | Just (LeanCheckException messages e') <- fromException e -> throw (addMessages messages e')
-        | otherwise -> throw e
-      Right (Just messages) -> pure $ Result "" (Failure Nothing (Reason (concat messages)))
-      Right Nothing -> pure $ Result "" Success
-    where addMessages messages (HUnit.HUnitFailure loc r) = HUnit.HUnitFailure loc $ case r of
-            HUnit.Reason s -> HUnit.Reason (intercalate "\n" messages ++ "\n" ++ s)
-            HUnit.ExpectedButGot Nothing expected actual -> HUnit.ExpectedButGot (Just (concat messages)) expected actual
-            HUnit.ExpectedButGot (Just preface) expected actual -> HUnit.ExpectedButGot (Just (intercalate "\n" messages ++ preface)) expected actual
-
-
-class IOTestable t where
-  -- 'resultiers', lifted into 'IO'.
-  ioResultTiers :: t -> [[IO ([String], Bool)]]
-
-instance IOTestable (IO ()) where
-  ioResultTiers action = [[ (action >> pure ([], True)) `catch` (throw . LeanCheckException []) ]]
-
-instance (IOTestable b, Show a, Listable a) => IOTestable (a -> b) where
-  ioResultTiers p = concatMapT (resultiersFor p) tiers
-
-instance IOTestable Bool where
-  ioResultTiers p = [[ pure ([], p) ]]
-
-instance Show a => IOTestable (ForAll a) where
-  ioResultTiers (ForAll tiers property) = concatMapT (resultiersFor property) tiers
-
-resultiersFor :: (IOTestable b, Show a) => (a -> b) -> a -> [[IO ([String], Bool)]]
-resultiersFor p x = fmap (eval x) <$> ioResultTiers (p x)
-
-eval :: Show a => a -> IO ([String], Bool) -> IO ([String], Bool)
-eval x action = first (prepend x) <$> action
-  `catch` \ (LeanCheckException messages failure) -> throw (LeanCheckException (prepend x messages) failure)
-  where prepend x = (showsPrec 11 x "":)
-
-
--- | 'counterExamples', lifted into 'IO'.
-iocounterExamples :: IOTestable a => Int -> a -> IO [[String]]
-iocounterExamples n = fmap (fmap fst . filter (not . snd)) . sequenceA . take n . concat . ioResultTiers
-
--- | 'counterExample', lifted into 'IO'.
-iocounterExample :: IOTestable a => Int -> a -> IO (Maybe [String])
-iocounterExample n = fmap listToMaybe . iocounterExamples n
-
-
-data LeanCheckException = LeanCheckException [String] HUnit.HUnitFailure
-  deriving (Show)
-
-instance Exception LeanCheckException