diff --git a/kmeans-par.cabal b/kmeans-par.cabal
--- a/kmeans-par.cabal
+++ b/kmeans-par.cabal
@@ -1,5 +1,5 @@
 name:                kmeans-par
-version:             1.4.1
+version:             1.4.2
 synopsis:            Sequential and parallel implementations of Lloyd's algorithm.
 license:             MIT
 license-file:        LICENSE
diff --git a/src/Algorithms/Lloyd/Sequential.lhs b/src/Algorithms/Lloyd/Sequential.lhs
--- a/src/Algorithms/Lloyd/Sequential.lhs
+++ b/src/Algorithms/Lloyd/Sequential.lhs
@@ -102,7 +102,7 @@
 >
 > assign :: Metric a => (Vector Double -> a) -> Vector Cluster -> Vector Point -> Vector (Vector Point)
 > assign metric clusters points = let nc = length clusters in create $ do
->   vector <- MV.replicate (nc+1) empty
+>   vector <- MV.replicate nc empty
 >   points `forM_` \point -> do
 >     let cluster  = closestCluster metric clusters point
 >         position = identifier cluster