diff --git a/src/Compiler.jl b/src/Compiler.jl
index 56c5b413dd..025a171b30 100644
--- a/src/Compiler.jl
+++ b/src/Compiler.jl
@@ -691,7 +691,7 @@ const SUM_TO_CONV = Ref(false)
 const AGGRESSIVE_SUM_TO_CONV = Ref(false)
 const AGGRESSIVE_PROPAGATION = Ref(false)
 const DUS_SLICE_SIMPLIFY = Ref(true)
-const CONCATS_TO_DUS = Ref(false)
+const CONCATS_TO_DUS = Ref(true)
 
 # Optimization passes via transform dialect
 function optimization_passes(
@@ -768,7 +768,6 @@ function optimization_passes(
         "iota_simplify<16>($max_constant_threshold)",
         "broadcast_in_dim_simplify<16>($max_constant_threshold)",
         "convert_concat<1>",
-        "dynamic_update_to_concat<1>",
         "slice_of_dynamic_update<1>",
         "slice_elementwise<1>",
         "dot_reshape_dot<1>",
@@ -1177,8 +1176,16 @@ function optimization_passes(
         )
     end
 
+    if !CONCATS_TO_DUS[]
+        push!(transform_passes_list, "dynamic_update_to_concat<1>")
+    end
+
     lower_transform_passes = copy(transform_passes_list)
 
+    if CONCATS_TO_DUS[]
+        push!(transform_passes_list, "dynamic_update_to_concat<1>")
+    end
+
     if recognize_comms
         append!(
             transform_passes_list,
@@ -1198,6 +1205,14 @@ function optimization_passes(
         ],
         ",",
     )
+    if CONCATS_TO_DUS[]
+        transform_passes =
+            transform_passes *
+            ",enzyme-hlo-generate-td{patterns=concat_to_onedim_dus},transform-interpreter,enzyme-hlo-remove-transform"
+        if lower_comms
+            push!(lower_transform_passes, "concat_to_onedim_dus")
+        end
+    end
     func_passes = join(["canonicalize", "cse", "canonicalize", transform_passes], ",")
     if lower_comms
         func_passes =
@@ -1206,12 +1221,6 @@ function optimization_passes(
             join(lower_transform_passes, ';') *
             "},transform-interpreter,enzyme-hlo-remove-transform"
     end
-    if CONCATS_TO_DUS[]
-        push!(
-            transform_passes_list,
-            "enzyme-hlo-generate-td{patterns=concat_to_onedim_dus},transform-interpreter,enzyme-hlo-remove-transform",
-        )
-    end
     passes = String[]
     if compile_options.inline
         push!(passes, "inline{default-pipeline=canonicalize max-iterations=4}")
diff --git a/src/ConcreteRArray.jl b/src/ConcreteRArray.jl
index 1eff7b4b9d..7e0c1bddff 100644
--- a/src/ConcreteRArray.jl
+++ b/src/ConcreteRArray.jl
@@ -406,7 +406,9 @@ end
 
 Base.similar(a::ConcretePJRTArray, dims::Dims) = similar(a, eltype(a), dims)
 
-@inline function Base.similar(AT::Type{<:ConcretePJRTArray{T}}, dims; kwargs...) where {T}
+@inline function Base.similar(
+    AT::Type{<:ConcretePJRTArray{T}}, dims::Dims; kwargs...
+) where {T}
     return Base.similar(AT, T, dims; kwargs...)
 end
 
@@ -416,7 +418,7 @@ function Base.similar(a::ConcreteIFRTArray{T}, ::Type{S}=T, dims::Dims=size(a))
     )
 end
 Base.similar(a::ConcreteIFRTArray, dims::Dims) = similar(a, eltype(a), dims)
-function Base.similar(::Type{ConcreteIFRTArray{T}}, dims) where {T}
+function Base.similar(::Type{ConcreteIFRTArray{T}}, dims::Dims) where {T}
     return ConcreteIFRTArray(similar(Array{T}, dims))
 end
 
diff --git a/test/indexing.jl b/test/indexing.jl
index 9487ecbe4a..9a4aad4a3c 100644
--- a/test/indexing.jl
+++ b/test/indexing.jl
@@ -47,6 +47,18 @@ end
     @test y ≈ Array(y_ra)
 end
 
+function write_row_simple!(xs_mut, i, v)
+    xs_mut[:, i] = v
+    return nothing
+end
+@testset "setindex: DUS" begin
+    x_ra = similar(ConcreteRArray{Float64}, (76, 100))
+    y_ra = similar(ConcreteRArray{Float64}, 76)
+    hlo = @code_hlo write_row_simple!(x_ra, 1, y_ra)
+    @test contains(repr(hlo), "dynamic_update_slice")
+    @test !contains(repr(hlo), "concatenate")
+end
+
 function maskset!(y, x)
     y[:] = x
     return nothing