diff --git a/src/backend/mxnet/graph.jl b/src/backend/mxnet/graph.jl
index 70fc413f..1d074a19 100644
--- a/src/backend/mxnet/graph.jl
+++ b/src/backend/mxnet/graph.jl
@@ -18,6 +18,7 @@ node(x::Tuple) = map(node, x)
 node(x::mx.SymbolicNode) = x
 
 graph(::typeof(tuple), args...) = (args...,)
+graph(::typeof(identity), x) = x
 graph(::typeof(getindex), t::Tuple, n::Integer) = t[n]
 graph(::typeof(.+), args...) = mx.broadcast_plus(args...)
 graph(::typeof(.*), args...) = mx.broadcast_mul(args...)
diff --git a/test/backend/common.jl b/test/backend/common.jl
new file mode 100644
index 00000000..1ed0122c
--- /dev/null
+++ b/test/backend/common.jl
@@ -0,0 +1,57 @@
+@net type TLP
+  first
+  second
+  function (x)
+    l1 = σ(first(x))
+    l2 = softmax(second(l1))
+  end
+end
+
+function test_tupleio(bk)
+  @testset "Tuple I/O" begin
+    val = [1,2,3]
+    tup = ([1,2,3],[4,5,6])
+    @test bk(@net x -> (identity(x),))(val) == (val,)
+    @test bk(@net x -> x[1].*x[2])(tup) == [4,10,18]
+  end
+end
+
+function test_recurrence(bk)
+  @testset "Recurrence" begin
+    seq = batchone(Seq(rand(10) for i = 1:3))
+    r = unroll(Recurrent(10, 5), 3)
+    rm = bk(r)
+    @test r(seq) ≈ rm(seq)
+  end
+end
+
+function test_back(bk)
+  @testset "Backward Pass" begin
+    xs, ys = rand(1, 20), rand(1, 20)
+    d = Affine(20, 10)
+    dm = bk(d)
+    d′ = deepcopy(d)
+    @test dm(xs) ≈ d(xs)
+    @test dm(xs) ≈ d′(xs)
+
+    Δ = back!(dm, randn(1, 10), xs)
+    @test length(Δ[1]) == 20
+    update!(dm, 0.1)
+
+    @test dm(xs) ≈ d(xs)
+    @test dm(xs) ≉ d′(xs)
+  end
+end
+
+function test_stacktrace(bk)
+  @testset "Stack Traces" begin
+    model = TLP(Affine(10, 20), Affine(21, 15))
+    dm = bk(model)
+    e = try dm(rand(1, 10))
+    catch e e end
+
+    @test isa(e, DataFlow.Interpreter.Exception)
+    @test e.trace[1].func == Symbol("Flux.Affine")
+    @test e.trace[2].func == :TLP
+  end
+end
diff --git a/test/backend/mxnet.jl b/test/backend/mxnet.jl
index 3bd1927f..29e51dd2 100644
--- a/test/backend/mxnet.jl
+++ b/test/backend/mxnet.jl
@@ -9,30 +9,10 @@ d = Affine(20, 10)
 dm = mxnet(d)
 @test d(xs) ≈ dm(xs)
 
-@testset "Tuple I/O" begin
-  @test mxnet(@net x -> (x,))([1,2,3]) == ([1,2,3],)
-  @test mxnet(@net x -> x[1].*x[2])(([1,2,3],[4,5,6])) == [4,10,18]
-end
-
-@testset "Recurrence" begin
-  seq = batchone(Seq(rand(10) for i = 1:3))
-  r = unroll(Recurrent(10, 5), 3)
-  rm = mxnet(r)
-  @test r(seq) ≈ rm(seq)
-end
-
-@testset "Backward Pass" begin
-  d′ = deepcopy(d)
-  @test dm(xs) ≈ d(xs)
-  @test dm(xs) ≈ d′(xs)
-
-  Δ = back!(dm, randn(1, 10), xs)
-  @test length(Δ[1]) == 20
-  update!(dm, 0.1)
-
-  @test dm(xs) ≈ d(xs)
-  @test dm(xs) ≉ d′(xs)
-end
+test_tupleio(mxnet)
+test_recurrence(mxnet)
+test_stacktrace(mxnet)
+test_back(mxnet)
 
 @testset "Native interface" begin
   f = mx.FeedForward(Chain(d, softmax))
@@ -45,16 +25,4 @@ end
   @test mx.infer_shape(f.arch, data = (20, 20, 5, 1))[2] == [(10, 1)]
 end
 
-@testset "Stack Traces" begin
-  model = TLP(Affine(10, 20), Affine(21, 15))
-  info("The following warning is normal")
-  dm = mxnet(model)
-  e = try dm(rand(1, 10))
-  catch e e end
-
-  @test isa(e, DataFlow.Interpreter.Exception)
-  @test e.trace[1].func == Symbol("Flux.Affine")
-  @test e.trace[2].func == :TLP
-end
-
 end
diff --git a/test/backend/tensorflow.jl b/test/backend/tensorflow.jl
index 5d75d210..ab9d4af7 100644
--- a/test/backend/tensorflow.jl
+++ b/test/backend/tensorflow.jl
@@ -9,17 +9,9 @@ d = Affine(20, 10)
 dt = tf(d)
 @test d(xs) ≈ dt(xs)
 
-@testset "Tuple I/O" begin
-  @test tf(@net x -> (identity(x),))([1,2,3]) == ([1,2,3],)
-  @test tf(@net x -> x[1].*x[2])(([1,2,3],[4,5,6])) == [4,10,18]
-end
-
-@testset "Recurrence" begin
-  seq = batchone(Seq(rand(10) for i = 1:3))
-  r = unroll(Recurrent(10, 5), 3)
-  rm = tf(r)
-  @test r(seq) ≈ rm(seq)
-end
+test_tupleio(tf)
+test_recurrence(tf)
+test_stacktrace(tf)
 
 @testset "Tensor interface" begin
   sess = TensorFlow.Session()
@@ -30,15 +22,4 @@ end
   @test run(sess, Y, Dict(X=>xs)) ≈ d(xs)
 end
 
-@testset "Stack Traces" begin
-  model = TLP(Affine(10, 20), Affine(21, 15))
-  dm = tf(model)
-  e = try dm(rand(1, 10))
-  catch e e end
-
-  @test isa(e, DataFlow.Interpreter.Exception)
-  @test e.trace[1].func == Symbol("Flux.Affine")
-  @test e.trace[2].func == :TLP
-end
-
 end
diff --git a/test/basic.jl b/test/basic.jl
index 708e8f83..56ef16d5 100644
--- a/test/basic.jl
+++ b/test/basic.jl
@@ -1,3 +1,6 @@
+syntax(v::Vertex) = prettify(DataFlow.syntax(v))
+syntax(x) = syntax(graph(x))
+
 @testset "Basics" begin
 
 xs = randn(1, 10)
diff --git a/test/runtests.jl b/test/runtests.jl
index e52c33cd..e110725e 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -2,9 +2,6 @@ using Flux, DataFlow, MacroTools, Base.Test
 using Flux: graph, Param, unsqueeze
 using DataFlow: Line, Frame
 
-syntax(v::Vertex) = prettify(DataFlow.syntax(v))
-syntax(x) = syntax(graph(x))
-
 macro mxonly(ex)
   :(Base.find_in_path("MXNet") ≠ nothing && $(esc(ex)))
 end
@@ -13,16 +10,9 @@ macro tfonly(ex)
   :(Base.find_in_path("TensorFlow") ≠ nothing && $(esc(ex)))
 end
 
-@net type TLP
-  first
-  second
-  function (x)
-    l1 = σ(first(x))
-    l2 = softmax(second(l1))
-  end
-end
-
 include("batching.jl")
+include("backend/common.jl")
+
 include("basic.jl")
 include("recurrent.jl")
 @tfonly include("backend/tensorflow.jl")