diff --git a/src/HordeAd/Core/OpsConcrete.hs b/src/HordeAd/Core/OpsConcrete.hs
index 3352db2a7..5f683ead1 100644
--- a/src/HordeAd/Core/OpsConcrete.hs
+++ b/src/HordeAd/Core/OpsConcrete.hs
@@ -629,17 +629,28 @@ tdot0R t u = OR.toVector t LA.<.> OR.toVector u
 -- TODO: try to weave a similar magic as in tindex0R
 -- TODO: for the non-singleton case see
 -- https://github.com/Mikolaj/horde-ad/pull/81#discussion_r1096532164
-updateNR :: forall n m a. GoodScalar a
-         => RepN (TKR (n + m) a) -> [(IxROf RepN n, RepN (TKR m a))]
-         -> RepN (TKR (n + m) a)
-updateNR arr upd =
-  let values = Nested.rtoVector $ unRepN arr
-      sh = rshape arr
-      f !t (ix, u) =
-        let v = Nested.rtoVector $ unRepN u
-            i = fromIntegral $ unRepN $ toLinearIdx @n @m fromIntegral sh ix
-        in V.concat [V.take i t, v, V.drop (i + V.length v) t]
-  in RepN $ Nested.rfromVector sh (foldl' f values upd)
+updateNR :: forall n m a. (KnownNat n, KnownNat m, TensorKind2 a)
+         => RepN (TKR2 (n + m) a) -> [(IxROf RepN n, RepN (TKR2 m a))]
+         -> RepN (TKR2 (n + m) a)
+updateNR arr upd = case stensorKind @a of
+  STKScalar{} ->
+    let values = Nested.rtoVector $ unRepN arr
+        sh = rshape arr
+        f !t (ix, u) =
+          let v = Nested.rtoVector $ unRepN u
+              i = fromIntegral $ unRepN $ toLinearIdx @n @m fromIntegral sh ix
+          in V.concat [V.take i t, v, V.drop (i + V.length v) t]
+    in RepN $ Nested.rfromVector sh (foldl' f values upd)
+  _ ->
+    let arrNested = rnest (SNat @n) arr
+        shNested = rshape arrNested
+        f i v = case lookup (fromLinearIdx
+                               @n (RepN . fromIntegral)
+                               shNested ((RepN . fromIntegral) i)) upd of
+          Just u -> rnest (SNat @0) u
+          Nothing -> v
+    in runNest $ rfromList0N shNested
+       $ imap f $ runravelToList $ rflatten arrNested
 
 tminIndexR
   :: forall r r2 n.
@@ -853,22 +864,37 @@ tgatherZ1R k t f = case stensorKind @r of
 -- TODO: try to weave a similar magic as in tindex0R
 -- TODO: for the non-singleton case see
 -- https://github.com/Mikolaj/horde-ad/pull/81#discussion_r1096532164
-updateNS :: forall n sh r. (GoodScalar r, KnownShS sh, KnownShS (Drop n sh))
-         => RepN (TKS sh r)
-         -> [(IxSOf RepN (Take n sh), RepN (TKS (Drop n sh) r))]
-         -> RepN (TKS sh r)
-updateNS arr upd =
-  let values = Nested.stoVector $ unRepN arr
-      sh = knownShS @sh
-      f !t (ix, u) =
-        let v = Nested.stoVector $ unRepN u
-            i = gcastWith (unsafeCoerce Refl
-                           :: sh :~: Take n sh ++ Drop n sh)
-                $ fromIntegral $ unRepN
-                $ ShapedList.toLinearIdx @(Take n sh) @(Drop n sh)
-                                         fromIntegral sh ix
-        in V.concat [V.take i t, v, V.drop (i + V.length v) t]
-  in RepN $ Nested.sfromVector knownShS (foldl' f values upd)
+updateNS :: forall n sh r.
+            ( TensorKind2 r, KnownShS sh, KnownShS (Drop n sh)
+            , KnownShS (Take n sh) )
+         => RepN (TKS2 sh r)
+         -> [(IxSOf RepN (Take n sh), RepN (TKS2 (Drop n sh) r))]
+         -> RepN (TKS2 sh r)
+updateNS arr upd = case stensorKind @r of
+  STKScalar{} ->
+    let values = Nested.stoVector $ unRepN arr
+        sh = knownShS @sh
+        f !t (ix, u) =
+          let v = Nested.stoVector $ unRepN u
+              i = gcastWith (unsafeCoerce Refl
+                             :: sh :~: Take n sh ++ Drop n sh)
+                  $ fromIntegral $ unRepN
+                  $ ShapedList.toLinearIdx @(Take n sh) @(Drop n sh)
+                                           fromIntegral sh ix
+          in V.concat [V.take i t, v, V.drop (i + V.length v) t]
+    in RepN $ Nested.sfromVector knownShS (foldl' f values upd)
+  _ -> case shsProduct (knownShS @(Take n sh)) of
+    SNat ->
+      gcastWith (unsafeCoerce Refl :: sh :~: Take n sh ++ Drop n sh) $
+      let arrNested = snest (knownShS @(Take n sh)) arr
+          shNested = sshape arrNested
+          f i v = case lookup (ShapedList.fromLinearIdx
+                                 @(Take n sh) (RepN . fromIntegral)
+                                 shNested ((RepN . fromIntegral) i)) upd of
+            Just u -> snest (knownShS @'[]) u
+            Nothing -> v
+      in sunNest @_ @(Take n sh) $ sfromList0N
+         $ imap f $ sunravelToList $ sflatten arrNested
 
 tminIndexS
   :: forall n sh r r2.