diff --git a/REQUIRE b/REQUIRE
index df9c6322..7164de5a 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,4 +1,4 @@
-julia 0.7-
+julia 0.7
 Juno
 MacroTools 0.3.3
 NNlib
diff --git a/src/layers/basic.jl b/src/layers/basic.jl
index d461c95c..f7344484 100644
--- a/src/layers/basic.jl
+++ b/src/layers/basic.jl
@@ -21,8 +21,8 @@ struct Chain
   Chain(xs...) = new([xs...])
 end
 
-@forward Chain.layers Base.getindex, Base.first, Base.last, Base.endof, Base.push!
-@forward Chain.layers Base.start, Base.next, Base.done
+@forward Chain.layers Base.getindex, Base.first, Base.last, Base.lastindex, Base.push!
+@forward Chain.layers Base.iterate
 
 children(c::Chain) = c.layers
 mapchildren(f, c::Chain) = Chain(f.(c.layers)...)
diff --git a/src/tracker/back.jl b/src/tracker/back.jl
index 04f5c231..774123b4 100644
--- a/src/tracker/back.jl
+++ b/src/tracker/back.jl
@@ -70,7 +70,7 @@ struct Params
   Params(xs) = new(IdSet(xs))
 end
 
-@forward Params.params Base.start, Base.next, Base.done
+@forward Params.params Base.iterate, Base.length
 
 function Base.show(io::IO, ps::Params)
   print(io, "Params([")
@@ -86,6 +86,8 @@ Base.show(io::IO, ps::Grads) = println(io, "Grads(...)")
 
 Grads() = Grads(IdDict())
 
+@forward Grads.grads Base.setindex!, Base.haskey, Base.length, Base.iterate
+
 Grads(ps::Params) = Grads(IdDict(tracker(p) => init_grad(data(p)) for p in ps))
 
 Base.getindex(g::Grads, x::Tracked) = g.grads[x]
@@ -94,7 +96,6 @@ function Base.getindex(g::Grads, x)
   g[tracker(x)]
 end
 
-@forward Grads.grads Base.setindex!, Base.haskey
 
 accum!(g::Grads, x, Δ) = g[x] = haskey(g, x) ? g[x] .+ Δ : Δ
 
diff --git a/src/tracker/idset.jl b/src/tracker/idset.jl
index 1bbfec09..62d5190e 100644
--- a/src/tracker/idset.jl
+++ b/src/tracker/idset.jl
@@ -20,6 +20,8 @@ Base.similar(s::IdSet, T::Type) = IdSet{T}()
 
 @forward IdSet.dict Base.length
 
-Base.start(s::IdSet) = start(keys(s.dict))
-Base.next(s::IdSet, st) = next(keys(s.dict), st)
-Base.done(s::IdSet, st) = done(keys(s.dict), st)
+function Base.iterate(v::IdSet, state...)
+  y = Base.iterate(keys(v.dict), state...)
+  y === nothing && return nothing
+  return (y[1], y[2])
+end
\ No newline at end of file
diff --git a/test/runtests.jl b/test/runtests.jl
index 6d698784..fcda4e82 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,6 +1,7 @@
 using Flux, Test, Random
+using Random
 
-srand(0)
+Random.seed!(0)
 
 @testset "Flux" begin
 
diff --git a/test/tracker.jl b/test/tracker.jl
index d504f0a4..768cc4f7 100644
--- a/test/tracker.jl
+++ b/test/tracker.jl
@@ -5,13 +5,13 @@ using NNlib: conv
 using Printf: @sprintf
 using LinearAlgebra: diagm, dot, LowerTriangular, norm
 using Statistics: mean, std
+using Random
 # using StatsBase
 
 gradtest(f, xs::AbstractArray...) = gradcheck((xs...) -> sum(sin.(f(xs...))), xs...)
-gradtest(f, dims...) = gradtest(f, rand.(dims)...)
+gradtest(f, dims...) = gradtest(f, rand.(Float64, dims)...)
 
 @testset "Tracker" begin
-
 @test gradtest((x, W, b) -> σ.(W*x .+ b), 5, (2,5), 2)
 @test gradtest((x, W, b) -> σ.(W*x .+ b), (5,3), (2,5), 2)
 @test gradtest((x, W, b) -> logσ.(W*x .+ b), 5, (2,5), 2)
diff --git a/test/utils.jl b/test/utils.jl
index 6fb28e31..5e1b0ef0 100644
--- a/test/utils.jl
+++ b/test/utils.jl
@@ -1,6 +1,7 @@
 using Flux: throttle, initn, glorot_uniform, glorot_normal, jacobian
 using StatsBase: std
 using Dates
+using Random
 
 @testset "Throttle" begin
   @testset "default behaviour" begin
@@ -61,7 +62,7 @@ end
 
 @testset "Initialization" begin
   # Set random seed so that these tests don't fail randomly
-  srand(0)
+  Random.seed!(0)
   # initn() should yield a kernel with stddev ~= 1e-2
   v = initn(10, 10)
   @test std(v) > 0.9*1e-2