diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,10 @@
 
 ## WIP
 
+## [1.4.3.1] - 2020-12-13
+
+- Fix Bits instance, shiftl and shiftr were incorrect
+
 ## [1.4.3] - 2020-12-08
 
 - Add Primitive flavour of sized vectors
diff --git a/package.yaml b/package.yaml
--- a/package.yaml
+++ b/package.yaml
@@ -1,5 +1,5 @@
 name: vector-sized
-version: 1.4.3
+version: 1.4.3.1
 synopsis: Size tagged vectors
 description: Please see README.md
 category: Data
diff --git a/src/Data/Vector/Generic/Sized.hs b/src/Data/Vector/Generic/Sized.hs
--- a/src/Data/Vector/Generic/Sized.hs
+++ b/src/Data/Vector/Generic/Sized.hs
@@ -247,6 +247,7 @@
 
 import Data.Vector.Generic.Sized.Internal
 import qualified Data.Vector.Generic as VG
+import qualified Data.Vector.Generic.Mutable as VGM
 import qualified Data.Vector as Boxed
 import qualified Data.Vector.Storable as Storable
 import qualified Data.Vector.Unboxed as Unboxed
@@ -260,6 +261,7 @@
 import Data.Finite hiding (shift)
 import Data.Finite.Internal
 import Data.Proxy
+import qualified Control.Exception as Exception
 import Control.Monad (mzero)
 import Control.Monad.Primitive
 import Control.Monad.ST
@@ -1950,11 +1952,6 @@
     (.|.) = coerce ((.|.) @(v a))
     xor   = coerce (xor   @(v a))
     complement = coerce (complement @(v a))
-    shiftL = coerce (shiftL @(v a))
-    unsafeShiftL = coerce (unsafeShiftL @(v a))
-    shiftR = coerce (shiftR @(v a))
-    unsafeShiftR = coerce (unsafeShiftR @(v a))
-    shift  = coerce (shift  @(v a))
     rotate = coerce (rotate @(v a))
     rotateL = coerce (rotateL @(v a))
     rotateR = coerce (rotateR @(v a))
@@ -1974,6 +1971,33 @@
         SVGM.write v i (complement zeroBits)
       freeze v
     zeroBits = replicate zeroBits
+    -- need to do special stuff because they have to preserve vector size
+    shiftL xs i
+      | i < 0     = Exception.throw Exception.Overflow
+      | otherwise = unsafeShiftL xs i
+    unsafeShiftL (Vector xs) i
+        | i  == 0   = Vector xs
+        | i' == n   = replicate zeroBits
+        | otherwise = Vector $ runST $ do
+            u <- VGM.replicate n zeroBits
+            VG.unsafeCopy (VGM.unsafeDrop i' u) (VG.unsafeTake (n - i') xs)
+            VG.unsafeFreeze u
+      where
+        n   = fromInteger $ natVal (Proxy @n)
+        i' = min n i
+    shiftR xs i
+      | i < 0     = Exception.throw Exception.Overflow
+      | otherwise = unsafeShiftR xs i
+    unsafeShiftR (Vector xs) i
+        | i  == 0   = Vector xs
+        | i' == n   = replicate zeroBits
+        | otherwise = Vector $ runST $ do
+            u <- VGM.replicate n zeroBits
+            VG.unsafeCopy (VGM.unsafeTake (n - i') u) (VG.unsafeDrop i' xs)
+            VG.unsafeFreeze u
+      where
+        n  = fromInteger $ natVal (Proxy @n)
+        i' = min n i
 
 -- | Treats a bit vector as n times the size of the stored bits, reflecting
 -- the 'Bits' instance; does not necessarily reflect exact in-memory
diff --git a/vector-sized.cabal b/vector-sized.cabal
--- a/vector-sized.cabal
+++ b/vector-sized.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           vector-sized
-version:        1.4.3
+version:        1.4.3.1
 synopsis:       Size tagged vectors
 description:    Please see README.md
 category:       Data