diff --git a/Test/Loc/Hedgehog/Gen.hs b/Test/Loc/Hedgehog/Gen.hs
deleted file mode 100644
--- a/Test/Loc/Hedgehog/Gen.hs
+++ /dev/null
@@ -1,267 +0,0 @@
-{-# LANGUAGE ScopedTypeVariables #-}
-
-{- |
-
-Hedgehog generators for types defined in the /loc/ package.
-
--}
-module Test.Loc.Hedgehog.Gen
-  (
-  -- * Line
-    line, line', defMaxLine
-
-  -- * Column
-  , column, column', defMaxColumn
-
-  -- * Loc
-  , loc, loc'
-
-  -- * Span
-  , span, span'
-
-  -- * Area
-  , area, area'
-
-  -- * Generator bounds
-  , Bounds, boundsSize
-
-  ) where
-
-import Data.Loc (ToNat (..))
-import Data.Loc.Internal.Prelude
-import Data.Loc.Types
-
-import qualified Data.Loc as Loc
-
-import Hedgehog (Gen)
-import Prelude (Num (..))
-
-import qualified Data.List as List
-import qualified Data.Set as Set
-import qualified Hedgehog.Gen as Gen
-import qualified Hedgehog.Range as Range
-
-
---------------------------------------------------------------------------------
---  Parameter defaults
---------------------------------------------------------------------------------
-
--- | The default maximum line: 99.
-defMaxLine :: Line
-defMaxLine = 99
-
--- | The default maximum column number: 99.
-defMaxColumn :: Column
-defMaxColumn = 99
-
-
---------------------------------------------------------------------------------
---  Bounds
---------------------------------------------------------------------------------
-
--- | Inclusive lower and upper bounds on a range.
-type Bounds a = (a, a)
-
-{- |
-
-The size of a range specified by 'Bounds'.
-
-Assumes the upper bound is at least the lower bound.
-
--}
-boundsSize :: Num n => (n, n) -> n
-boundsSize (a, b) =
-  1 + b - a
-
-
---------------------------------------------------------------------------------
---  Pos
---------------------------------------------------------------------------------
-
-{- |
-
-@'pos' a b@ generates a number on the linear range /a/ to /b/.
-
--}
-pos :: (Monad m, ToNat n, Num n)
-  => Bounds n -- ^ Minimum and maximum value to generate
-  -> Gen m n
-pos (a, b) =
-  let
-    range = Range.linear (toNat a) (toNat b)
-  in
-    fromInteger . toInteger <$> Gen.integral range
-
-{- |
-
-@'line' a b@ generates a line number on the linear range /a/ to /b/.
-
--}
-line :: Monad m
-  => Bounds Line -- ^ Minimum and maximum line number
-  -> Gen m Line
-line = pos
-
-{- |
-
-Generates a line number within the default bounds @(1, 'defMaxLine')@.
-
--}
-line' :: Monad m => Gen m Line
-line' =
-  line (1, defMaxLine)
-
-{- |
-
-@'column' a b@ generates a column number on the linear range /a/ to /b/.
-
--}
-column :: Monad m
-  => Bounds Column -- ^ Minimum and maximum column number
-  -> Gen m Column
-column = pos
-
-{- |
-
-Generates a column number within the default bounds @(1, 'defMaxColumn')@.
-
--}
-column' :: Monad m => Gen m Column
-column' =
-  column (1, defMaxColumn)
-
-
---------------------------------------------------------------------------------
---  Loc
---------------------------------------------------------------------------------
-
-{- |
-
-@'loc' lineBounds columnBounds@ generates a 'Loc' with the line number
-bounded by @lineBounds@ and column number bounded by @columnBounds@.
-
--}
-loc :: Monad m
-  => Bounds Line   -- ^ Minimum and maximum line number
-  -> Bounds Column -- ^ Minimum and maximum column number
-  -> Gen m Loc
-loc lineBounds columnBounds =
-  Loc.loc <$> line   lineBounds
-          <*> column columnBounds
-
-{- |
-
-Generates a 'Loc' within the default line and column bounds.
-
--}
-loc' :: Monad m => Gen m Loc
-loc' =
-  loc (1, defMaxLine) (1, defMaxColumn)
-
-
---------------------------------------------------------------------------------
---  Span
---------------------------------------------------------------------------------
-
-{- |
-
-@'span' lineBounds columnBounds@ generates a 'Span' with start and end
-positions whose line numbers are bounded by @lineBounds@ and whose column
-numbers are bounded by @columnBounds@.
-
--}
-span :: forall m. Monad m
-  => Bounds Line   -- ^ Minimum and maximum line number
-  -> Bounds Column -- ^ Minimum and maximum column number
-  -> Gen m Span
-span lineBounds columnBounds@(minColumn, maxColumn) =
-  let
-    lines :: Gen m (Line, Line)
-    lines =
-      line lineBounds >>= \a ->
-      line lineBounds <&> \b ->
-      (min a b, max a b)
-
-    columnsDifferentLine :: Gen m (Column, Column)
-    columnsDifferentLine =
-      column columnBounds >>= \a ->
-      column columnBounds <&> \b ->
-      (a, b)
-
-    columnsSameLine :: Gen m (Column, Column)
-    columnsSameLine =
-      column (minColumn + 1, maxColumn) >>= \a ->
-      column columnBounds <&> \b ->
-      case compare a b of
-        EQ -> (a - 1, b)
-        LT -> (a, b)
-        GT -> (b, a)
-
-  in
-    lines >>= \(startLine, endLine) ->
-    (if startLine /= endLine
-        then columnsDifferentLine
-        else columnsSameLine
-    ) <&> \(startColumn, endColumn) ->
-
-    let
-      start = Loc.loc startLine startColumn
-      end   = Loc.loc endLine   endColumn
-
-    in
-      Loc.spanFromTo start end
-
-{- |
-
-Generates a 'Span' with start and end positions within the default line and
-column bounds.
-
--}
-span' :: Monad m => Gen m Span
-span' =
-  span (1, defMaxLine) (1, defMaxColumn)
-
-
---------------------------------------------------------------------------------
---  Area
---------------------------------------------------------------------------------
-
-{- |
-
-@'area' lineBounds columnBounds@ generates an 'Area' consisting of 'Span's
-with start and end positions whose line numbers are bounded by @lineBounds@
-and whose column numbers are bounded by @columnBounds@.
-
--}
-area :: forall m. Monad m
-  => Bounds Line   -- ^ Minimum and maximum line number
-  -> Bounds Column -- ^ Minimum and maximum column number
-  -> Gen m Area
-area lineBounds columnBounds =
-    fold . snd . mapAccumL f Nothing . Set.toAscList . Set.fromList <$> locs
-
-  where
-    gridSize :: Int = fromIntegral $ toNat (boundsSize lineBounds)
-                               `max` toNat (boundsSize columnBounds)
-
-    locs :: Gen m [Loc]
-      = loc lineBounds columnBounds
-      & List.repeat
-      & List.take (gridSize `div` 5)
-      & sequenceA
-
-    f :: Maybe Loc -> Loc -> (Maybe Loc, Area)
-    f prevLocMay newLoc =
-      case prevLocMay of
-        Just prevLoc -> (Nothing, Loc.areaFromTo prevLoc newLoc)
-        Nothing -> (Just newLoc, mempty)
-
-{- |
-
-Generates an 'Area' consisting of 'Span's with start and end positions within
-the default line and column bounds.
-
--}
-area' :: Monad m => Gen m Area
-area' =
-  area (1, defMaxLine) (1, defMaxColumn)
diff --git a/loc-test.cabal b/loc-test.cabal
--- a/loc-test.cabal
+++ b/loc-test.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           loc-test
-version:        0.1.2.1
+version:        0.1.3.0
 synopsis:       Test-related utilities related to the /loc/ package.
 
 description:    Test-related utilities related to the /loc/ package. Currently contains only
@@ -19,7 +19,7 @@
 
 library
   hs-source-dirs:
-      ./.
+      src
   default-extensions: NoImplicitPrelude
   ghc-options: -Wall
   build-depends:
diff --git a/src/Test/Loc/Hedgehog/Gen.hs b/src/Test/Loc/Hedgehog/Gen.hs
new file mode 100644
--- /dev/null
+++ b/src/Test/Loc/Hedgehog/Gen.hs
@@ -0,0 +1,267 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+
+{- |
+
+Hedgehog generators for types defined in the /loc/ package.
+
+-}
+module Test.Loc.Hedgehog.Gen
+  (
+  -- * Line
+    line, line', defMaxLine
+
+  -- * Column
+  , column, column', defMaxColumn
+
+  -- * Loc
+  , loc, loc'
+
+  -- * Span
+  , span, span'
+
+  -- * Area
+  , area, area'
+
+  -- * Generator bounds
+  , Bounds, boundsSize
+
+  ) where
+
+import Data.Loc (ToNat (..))
+import Data.Loc.Internal.Prelude
+import Data.Loc.Types
+
+import qualified Data.Loc as Loc
+
+import Hedgehog (Gen)
+import Prelude (Num (..))
+
+import qualified Data.List as List
+import qualified Data.Set as Set
+import qualified Hedgehog.Gen as Gen
+import qualified Hedgehog.Range as Range
+
+
+--------------------------------------------------------------------------------
+--  Parameter defaults
+--------------------------------------------------------------------------------
+
+-- | The default maximum line: 99.
+defMaxLine :: Line
+defMaxLine = 99
+
+-- | The default maximum column number: 99.
+defMaxColumn :: Column
+defMaxColumn = 99
+
+
+--------------------------------------------------------------------------------
+--  Bounds
+--------------------------------------------------------------------------------
+
+-- | Inclusive lower and upper bounds on a range.
+type Bounds a = (a, a)
+
+{- |
+
+The size of a range specified by 'Bounds'.
+
+Assumes the upper bound is at least the lower bound.
+
+-}
+boundsSize :: Num n => (n, n) -> n
+boundsSize (a, b) =
+  1 + b - a
+
+
+--------------------------------------------------------------------------------
+--  Pos
+--------------------------------------------------------------------------------
+
+{- |
+
+@'pos' a b@ generates a number on the linear range /a/ to /b/.
+
+-}
+pos :: (ToNat n, Num n)
+  => Bounds n -- ^ Minimum and maximum value to generate
+  -> Gen n
+pos (a, b) =
+  let
+    range = Range.linear (toNat a) (toNat b)
+  in
+    fromInteger . toInteger <$> Gen.integral range
+
+{- |
+
+@'line' a b@ generates a line number on the linear range /a/ to /b/.
+
+-}
+line
+  :: Bounds Line -- ^ Minimum and maximum line number
+  -> Gen Line
+line = pos
+
+{- |
+
+Generates a line number within the default bounds @(1, 'defMaxLine')@.
+
+-}
+line' :: Gen Line
+line' =
+  line (1, defMaxLine)
+
+{- |
+
+@'column' a b@ generates a column number on the linear range /a/ to /b/.
+
+-}
+column
+  :: Bounds Column -- ^ Minimum and maximum column number
+  -> Gen Column
+column = pos
+
+{- |
+
+Generates a column number within the default bounds @(1, 'defMaxColumn')@.
+
+-}
+column' :: Gen Column
+column' =
+  column (1, defMaxColumn)
+
+
+--------------------------------------------------------------------------------
+--  Loc
+--------------------------------------------------------------------------------
+
+{- |
+
+@'loc' lineBounds columnBounds@ generates a 'Loc' with the line number
+bounded by @lineBounds@ and column number bounded by @columnBounds@.
+
+-}
+loc
+  :: Bounds Line   -- ^ Minimum and maximum line number
+  -> Bounds Column -- ^ Minimum and maximum column number
+  -> Gen Loc
+loc lineBounds columnBounds =
+  Loc.loc <$> line   lineBounds
+          <*> column columnBounds
+
+{- |
+
+Generates a 'Loc' within the default line and column bounds.
+
+-}
+loc' :: Gen Loc
+loc' =
+  loc (1, defMaxLine) (1, defMaxColumn)
+
+
+--------------------------------------------------------------------------------
+--  Span
+--------------------------------------------------------------------------------
+
+{- |
+
+@'span' lineBounds columnBounds@ generates a 'Span' with start and end
+positions whose line numbers are bounded by @lineBounds@ and whose column
+numbers are bounded by @columnBounds@.
+
+-}
+span
+  :: Bounds Line   -- ^ Minimum and maximum line number
+  -> Bounds Column -- ^ Minimum and maximum column number
+  -> Gen Span
+span lineBounds columnBounds@(minColumn, maxColumn) =
+  let
+    lines :: Gen (Line, Line)
+    lines =
+      line lineBounds >>= \a ->
+      line lineBounds <&> \b ->
+      (min a b, max a b)
+
+    columnsDifferentLine :: Gen (Column, Column)
+    columnsDifferentLine =
+      column columnBounds >>= \a ->
+      column columnBounds <&> \b ->
+      (a, b)
+
+    columnsSameLine :: Gen (Column, Column)
+    columnsSameLine =
+      column (minColumn + 1, maxColumn) >>= \a ->
+      column columnBounds <&> \b ->
+      case compare a b of
+        EQ -> (a - 1, b)
+        LT -> (a, b)
+        GT -> (b, a)
+
+  in
+    lines >>= \(startLine, endLine) ->
+    (if startLine /= endLine
+        then columnsDifferentLine
+        else columnsSameLine
+    ) <&> \(startColumn, endColumn) ->
+
+    let
+      start = Loc.loc startLine startColumn
+      end   = Loc.loc endLine   endColumn
+
+    in
+      Loc.spanFromTo start end
+
+{- |
+
+Generates a 'Span' with start and end positions within the default line and
+column bounds.
+
+-}
+span' :: Gen Span
+span' =
+  span (1, defMaxLine) (1, defMaxColumn)
+
+
+--------------------------------------------------------------------------------
+--  Area
+--------------------------------------------------------------------------------
+
+{- |
+
+@'area' lineBounds columnBounds@ generates an 'Area' consisting of 'Span's
+with start and end positions whose line numbers are bounded by @lineBounds@
+and whose column numbers are bounded by @columnBounds@.
+
+-}
+area
+  :: Bounds Line   -- ^ Minimum and maximum line number
+  -> Bounds Column -- ^ Minimum and maximum column number
+  -> Gen Area
+area lineBounds columnBounds =
+    fold . snd . mapAccumL f Nothing . Set.toAscList . Set.fromList <$> locs
+
+  where
+    gridSize :: Int = fromIntegral $ toNat (boundsSize lineBounds)
+                               `max` toNat (boundsSize columnBounds)
+
+    locs :: Gen [Loc] =
+      loc lineBounds columnBounds
+      & List.repeat
+      & List.take (gridSize `div` 5)
+      & sequenceA
+
+    f :: Maybe Loc -> Loc -> (Maybe Loc, Area)
+    f prevLocMay newLoc =
+      case prevLocMay of
+        Just prevLoc -> (Nothing, Loc.areaFromTo prevLoc newLoc)
+        Nothing -> (Just newLoc, mempty)
+
+{- |
+
+Generates an 'Area' consisting of 'Span's with start and end positions within
+the default line and column bounds.
+
+-}
+area' :: Gen Area
+area' =
+  area (1, defMaxLine) (1, defMaxColumn)