diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,1 @@
+Various https://en.wikipedia.org/wiki/Line_drawing_algorithm
diff --git a/changes.txt b/changes.txt
--- a/changes.txt
+++ b/changes.txt
@@ -1,3 +1,9 @@
+0.2.0.0
+-------
+
+- Made `bresenham` polymorphic.
+- Released Sun 10 Nov 2019 15:13:29 CET.
+
 0.1.0.0
 -------
 
diff --git a/line-drawing.cabal b/line-drawing.cabal
--- a/line-drawing.cabal
+++ b/line-drawing.cabal
@@ -1,6 +1,6 @@
 cabal-version:       >=1.10
 name:                line-drawing
-version:             0.1.0.0
+version:             0.2.0.0
 synopsis:            raster line drawing
 description:         Line drawing algorithms to approximate a
                      line segment on discrete graphical media (raster).
@@ -14,7 +14,8 @@
 copyright:           © 2019 Francesco Ariis
 category:            Graphics
 build-type:          Simple
-extra-source-files:  changes.txt
+extra-source-files:  changes.txt,
+                     README
 
 library
   exposed-modules:     Line.Draw
diff --git a/src/Line/Draw.hs b/src/Line/Draw.hs
--- a/src/Line/Draw.hs
+++ b/src/Line/Draw.hs
@@ -1,4 +1,4 @@
---------------------------------------------------------------------------------
+-------------------------------------------------------------------------------
 -- |
 -- Module      :  Line.Draw
 -- Copyright   :  (C) 2019 Francesco Ariis
@@ -18,24 +18,20 @@
 -- [(0,0), (1,0), (2,1), (3,1), (4,2)]
 -- @
 --
---------------------------------------------------------------------------------
+-------------------------------------------------------------------------------
 
-module Line.Draw (
-                   Coords,
-                   bresenham
-                 )
+{-# Language ScopedTypeVariables #-}
+
+module Line.Draw ( bresenham )
         where
 
 import qualified Data.List  as L
 import qualified Data.Tuple as T
 
-type Coords = (Int, Int)
-type State  = (Int, Int, Int)
-          -- curr x, curr y, treshold
 
 -- | Rasterising a line using
 -- <https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm Bresenham's algorithm>.
-bresenham :: Coords -> Coords -> [Coords]
+bresenham :: Integral a => (a, a) -> (a, a) -> [(a, a)]
 bresenham x@(x1, y1) y@(x2, y2)
             | m1Check   = bresenhamBase x y
             | otherwise = let x' = T.swap x
@@ -50,28 +46,30 @@
 -- ANCILLARIES --
 -----------------
 
-bresenhamBase :: Coords -> Coords -> [Coords]
+bresenhamBase :: forall a . Integral a => (a, a) -> (a, a) -> [(a, a)]
 bresenhamBase (x1, y1) (x2, y2) =
         let -- first treshold
             ti = 2 * ady - adx
         in L.unfoldr f (x1, y1, ti)
     where
           -- slope
-          dx, dy, adx, ady :: Int
+          dx, dy, adx, ady :: a
           dx = x2 - x1
           dy = y2 - y1
           adx = abs dx
           ady = abs dy
 
           -- sign of increment
-          ix, iy :: Int -> Int
+          ix, iy :: a -> a
           ix | dx > 0    = (+1)
              | otherwise = (subtract 1)
           iy | dy > 0    = (+1)
              | otherwise = (subtract 1)
 
           -- step function, takes (x, y, treshold)
-          f :: State -> Maybe (Coords, State)
+                -- type State  = (Int, Int, Int)
+                -- curr x, curr y, treshold
+          f :: (a, a, a) -> Maybe ((a, a), (a, a, a))
           f (cx, cy, t)
               | abs cx > abs x2 = Nothing
               | otherwise       =
diff --git a/test/Line/DrawSpec.hs b/test/Line/DrawSpec.hs
--- a/test/Line/DrawSpec.hs
+++ b/test/Line/DrawSpec.hs
@@ -13,21 +13,24 @@
 
   describe "bresenham" $ do
     it "rasterises a simple line" $
-      bresenham (0, 0) (4, 4) `shouldBe`
+      bresenham (0 :: Int, 0) (4, 4) `shouldBe`
         [(0,0), (1,1), (2,2), (3,3), (4,4)]
+    it "rasterises a simple line starting from (1, 1)" $
+      bresenham (1 :: Int, 1) (4, 4) `shouldBe`
+        [(1,1), (2,2), (3,3), (4,4)]
     it "rasterises a line" $
-      bresenham (0, 0) (4, 2) `shouldBe`
+      bresenham (0 :: Int, 0) (4, 2) `shouldBe`
         [(0,0), (1,0), (2,1), (3,1), (4,2)]
     it "rasterises a line, quadrant 2, m<1" $
-      bresenham (0, 0) (-4, 2) `shouldBe`
+      bresenham (0 :: Int, 0) (-4, 2) `shouldBe`
         [(0,0), (-1,0), (-2,1), (-3,1), (-4,2)]
     it "rasterises a line, quadrant 3, m<1" $
-      bresenham (0, 0) (-4, -2) `shouldBe`
+      bresenham (0 :: Int, 0) (-4, -2) `shouldBe`
         [(0,0), (-1,0), (-2,-1), (-3,-1), (-4,-2)]
     it "rasterises a line, quadrant 1, m>1" $
-      bresenham (0, 0) (2, 4) `shouldBe`
+      bresenham (0 :: Int, 0) (2, 4) `shouldBe`
         [(0,0), (0,1), (1,2), (1,3), (2,4)]
     it "rasterises a line, quadrant 4, m>1" $
-      bresenham (0, 0) (2, -4) `shouldBe`
+      bresenham (0 :: Int, 0) (2, -4) `shouldBe`
         [(0,0), (0,-1), (1,-2), (1,-3), (2,-4)]