diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,12 +7,16 @@
 *Nov 13, 2018*
 
 *   <https://github.com/mstksg/hmatrix-vector-sized/releases/tag/v0.1.1.1>
-    
+
     Fix building on GHC 8.6.
 
 *   <https://github.com/mstksg/hmatrix-vector-sized/releases/tag/v0.1.1.2>
-    
+
     Fix tests building on GHC 8.6.
+
+*   <https://github.com/mstksg/hmatrix-vector-sized/releases/tag/v0.1.1.3>
+
+    Optimization for matrix converters.
 
 Version 0.1.1.0
 ---------------
diff --git a/hmatrix-vector-sized.cabal b/hmatrix-vector-sized.cabal
--- a/hmatrix-vector-sized.cabal
+++ b/hmatrix-vector-sized.cabal
@@ -1,13 +1,13 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.31.0.
+-- This file has been generated from package.yaml by hpack version 0.31.1.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 8e80ded1d28394026d3fe0117f363e0ba49be99cf24bdba7f7e79c2a83174970
+-- hash: 677d211149f0d40bd2024eacc652a3939c10f05a788fd1fc438aa4a7b14ca00c
 
 name:           hmatrix-vector-sized
-version:        0.1.1.2
+version:        0.1.1.3
 synopsis:       Conversions between hmatrix and vector-sized types
 description:    Conversions between statically sized types in hmatrix and vector-sized.
                 .
diff --git a/src/Numeric/LinearAlgebra/Static/Vector.hs b/src/Numeric/LinearAlgebra/Static/Vector.hs
--- a/src/Numeric/LinearAlgebra/Static/Vector.hs
+++ b/src/Numeric/LinearAlgebra/Static/Vector.hs
@@ -101,7 +101,7 @@
     -> H.L m n
 rowsL = (unsafeCoerce :: HU.Matrix Double -> H.L m n)
       . HU.fromRows
-      . map (unsafeCoerce :: H.R n -> HU.Vector Double)
+      . (unsafeCoerce :: [H.R n] -> [HU.Vector Double])
       . toList
 
 -- | Split an /hmatrix/ matrix (parameterized by its dimensions) to
@@ -123,7 +123,7 @@
     -> H.L m n
 colsL = (unsafeCoerce :: HU.Matrix Double -> H.L m n)
       . HU.fromColumns
-      . map (unsafeCoerce :: H.R m -> HU.Vector Double)
+      . (unsafeCoerce :: [H.R m] -> [HU.Vector Double])
       . toList
 
 -- | Split an /hmatrix/ complex matrix (parameterized by its dimensions) to
@@ -146,7 +146,7 @@
     -> H.M m n
 rowsM = (unsafeCoerce :: HU.Matrix H.ℂ -> H.M m n)
       . HU.fromRows
-      . map (unsafeCoerce :: H.C n -> HU.Vector H.ℂ)
+      . (unsafeCoerce :: [H.C n] -> [HU.Vector H.ℂ])
       . toList
 
 -- | Split an /hmatrix/ complex matrix (parameterized by its dimensions) to
@@ -169,7 +169,7 @@
     -> H.M m n
 colsM = (unsafeCoerce :: HU.Matrix H.ℂ -> H.M m n)
       . HU.fromColumns
-      . map (unsafeCoerce :: H.C m -> HU.Vector H.ℂ)
+      . (unsafeCoerce :: [H.C m] -> [HU.Vector H.ℂ])
       . toList
 
 -- | Shape a /vector-sized/ storable vector of elements into an /hmatrix/