diff --git a/examples/PortZygote/chainrules_patch.jl b/examples/PortZygote/chainrules_patch.jl
index 71807e1f9..76b706fc3 100644
--- a/examples/PortZygote/chainrules_patch.jl
+++ b/examples/PortZygote/chainrules_patch.jl
@@ -1,16 +1,16 @@
 import ChainRulesCore: rrule, @non_differentiable, NoTangent
 using Yao, Yao.AD
 
-function rrule(::typeof(apply!), reg::ArrayReg, block::AbstractBlock)
-    out = apply!(reg, block)
+function rrule(::typeof(apply), reg::ArrayReg, block::AbstractBlock)
+    out = apply(reg, block)
     out, function (outδ)
-        (in, inδ), paramsδ = apply_back((out, outδ), block)
+        (in, inδ), paramsδ = apply_back((copy(out), outδ), block)
         return (NoTangent(), inδ, paramsδ)
     end
 end
 
-function rrule(::typeof(dispatch!), block::AbstractBlock, params)
-    out = dispatch!(block, params)
+function rrule(::typeof(dispatch), block::AbstractBlock, params)
+    out = dispatch(block, params)
     out, function (outδ)
         (NoTangent(), NoTangent(), outδ)
     end
diff --git a/examples/PortZygote/gate_learning.jl b/examples/PortZygote/gate_learning.jl
index 30af24763..2deb7fbf1 100644
--- a/examples/PortZygote/gate_learning.jl
+++ b/examples/PortZygote/gate_learning.jl
@@ -20,8 +20,8 @@ Learn a general U4 gate. The optimizer is LBFGS.
 function learn_u4(u::AbstractMatrix; niter=100)
     ansatz = general_U4() * put(2, 1=>phase(0.0))  # initial values are 0, here, we attach a global phase.
     params = parameters(ansatz)
-    g!(G, x) = (dispatch!(ansatz, x); G .= Zygote.gradient(ansatz->loss(u, ansatz), ansatz)[1])
-    optimize(x->(dispatch!(ansatz, x); loss(u, ansatz)), g!, parameters(ansatz),
+    g!(G, x) = (ansatz=dispatch(ansatz, x); G .= Zygote.gradient(ansatz->loss(u, ansatz), ansatz)[1])
+    optimize(x->(ansatz=dispatch(ansatz, x); loss(u, ansatz)), g!, parameters(ansatz),
                     LBFGS(), Optim.Options(iterations=niter))
     println("final loss = $(loss(u,ansatz))")
     return ansatz
diff --git a/examples/PortZygote/shared_parameters.jl b/examples/PortZygote/shared_parameters.jl
index b4705003d..02602d824 100644
--- a/examples/PortZygote/shared_parameters.jl
+++ b/examples/PortZygote/shared_parameters.jl
@@ -8,8 +8,8 @@ h = YaoExtensions.heisenberg(5)
 
 function loss(h, c, θ) where N
     # the assign is nessesary!
-    c = dispatch!(c, fill(θ, nparameters(c)))
-    reg = apply!(zero_state(nqubits(c)), c)
+    c = dispatch(c, fill(θ, nparameters(c)))
+    reg = apply(zero_state(nqubits(c)), c)
     real(expect(h, reg))
 end
 
@@ -28,9 +28,9 @@ true_grad = sum(gparams)
 # the batched version
 function loss2(h, c, θ) where N
     # the assign is nessesary!
-    c = dispatch!(c, fill(θ, nparameters(c)))
+    c = dispatch(c, fill(θ, nparameters(c)))
     reg = zero_state(nqubits(c),nbatch=2)
-    reg = apply!(reg, c)
+    reg = apply(reg, c)
     sum(real(expect(h, reg)))
 end
 
diff --git a/examples/PortZygote/simple_example.jl b/examples/PortZygote/simple_example.jl
index 50bff360f..f3993c95f 100644
--- a/examples/PortZygote/simple_example.jl
+++ b/examples/PortZygote/simple_example.jl
@@ -8,7 +8,7 @@ dispatch!(c, :random)
 
 function loss(reg::AbstractRegister, circuit::AbstractBlock{N}) where N
     #copy(reg) |> circuit
-    reg = apply!(copy(reg), circuit)
+    reg = apply(copy(reg), circuit)
     st = state(reg)
     sum(real(st.*st))
 end