diff --git a/src/instructs.jl b/src/instructs.jl
index 0548afe..6ed8e35 100644
--- a/src/instructs.jl
+++ b/src/instructs.jl
@@ -305,7 +305,7 @@ for RG in [:Rx, :Ry, :Rz]
             ::Val{$(QuoteNode(RG))},
             locs::Tuple{Int},
             theta::Number
-        ) where {T, N}
+        ) where {T}
         YaoArrayRegister.instruct!(Val(2), state, Val($(QuoteNode(RG))), locs, (), (), theta)
         return state
     end
diff --git a/src/register.jl b/src/register.jl
index 7e7d1f2..cc493e9 100644
--- a/src/register.jl
+++ b/src/register.jl
@@ -279,9 +279,6 @@ end
 function YaoBlocks.expect(op::AbstractBlock, dm::CuDensityMatrix{D}) where D
     return tr(apply(ArrayReg{D}(dm.state), op).state)
 end
-function expect(op::Scale, reg::DensityMatrix)
-    factor(op) * expect(content(op), reg)
-end
 
 measure(
     ::ComputationalBasis,
@@ -289,4 +286,5 @@ measure(
     ::AllLocs;
     nshots::Int = 1,
     rng::AbstractRNG = Random.GLOBAL_RNG,
-) = YaoArrayRegister._measure(rng, basis(reg), Array(reg |> probs), nshots)
\ No newline at end of file
+) = YaoArrayRegister._measure(rng, basis(reg), Array(reg |> probs), nshots)
+
diff --git a/test/register.jl b/test/register.jl
index ff67f4c..18f1a0a 100644
--- a/test/register.jl
+++ b/test/register.jl
@@ -87,9 +87,9 @@ end
     @test size(res) == (32,)
     @test res2 == res
 
-    reg = repeat(ArrayReg([1,-1+0im]/sqrt(2.0)), 10) |> cu
+    reg = clone(ArrayReg([1,-1+0im]/sqrt(2.0)), 10) |> cu
     @test measure!(X, reg) |> mean ≈ -1
-    reg = repeat(ArrayReg([1.0,0+0im]), 1000)
+    reg = clone(ArrayReg([1.0,0+0im]), 1000)
     @test abs(measure!(X, reg) |> mean) < 0.1
 end
 
@@ -135,4 +135,5 @@ end
         reg = cughz_state(3; nbatch=b)
         @test cpu(reg) ≈ ghz_state(3; nbatch=b) && reg isa AbstractCuArrayReg
     end
-end
\ No newline at end of file
+end
+