diff --git a/src/FluxOptTools.jl b/src/FluxOptTools.jl
index 69b8a2f..4e88041 100644
--- a/src/FluxOptTools.jl
+++ b/src/FluxOptTools.jl
@@ -27,13 +27,13 @@ function optfuns(loss, pars::Union{Flux.Params, Zygote.Params})
     end
     fg! = function (F,G,w)
         copy!(pars, w)
-        if G != nothing
+        if !isnothing(G)
             l, back = Zygote.pullback(loss, pars)
             grads = back(1)
             copy!(G, grads)
             return l
         end
-        if F != nothing
+        if !isnothing(F)
             return loss()
         end
     end
diff --git a/test/runtests.jl b/test/runtests.jl
index 0284f10..b1ca43e 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -11,7 +11,7 @@ using FluxOptTools, Optim, Zygote, Flux, Plots, Test, Statistics, Random
 @info "Testing copy"
 
 m = Chain(Dense(1,5,tanh), Dense(5,5,tanh) , Dense(5,1))
-x = collect(LinRange(-pi,pi,100)')
+x = collect(LinRange{Float32}(-pi,pi,100)')
 y = sin.(x)
 sp = sortperm(x[:])
 
@@ -50,7 +50,7 @@ end
 # NOTE: tests below fail if they are in a testset, probably Zygote's fault
 
 m = Chain(Dense(1,5,tanh), Dense(5,5,tanh) , Dense(5,1))
-x = collect(LinRange(-pi,pi,100)')
+x = collect(LinRange{Float32}(-pi,pi,100)')
 y = sin.(x)
 sp = sortperm(x[:])
 
@@ -59,7 +59,7 @@ loss() = mean(abs2, m(x) .- y)
 Zygote.refresh()
 pars = Flux.params(m)
 
-opt = ADAM(0.01)
+opt = Flux.Adam(0.01)
 @show loss()
 for i = 1:500
     grads = Zygote.gradient(loss, pars)
@@ -84,12 +84,12 @@ losses_adam = map(1:10) do i
     @show i
     Random.seed!(i)
     m = Chain(Dense(1,5,tanh), Dense(5,5,tanh) , Dense(5,1))
-    x = collect(LinRange(-pi,pi,100)')
+    x = collect(LinRange{Float32}(-pi,pi,100)')
     y = sin.(x)
     loss() = mean(abs2, m(x) .- y)
     Zygote.refresh()
     pars = Flux.params(m)
-    opt = Flux.ADAM(0.2)
+    opt = Flux.Adam(0.2)
     trace = [loss()]
     for i = 1:500
         l,back = Zygote.pullback(loss, pars)
@@ -104,7 +104,7 @@ res_lbfgs = map(1:10) do i
     @show i
     Random.seed!(i)
     m = Chain(Dense(1,5,tanh), Dense(5,5,tanh) , Dense(5,1))
-    x = LinRange(-pi,pi,100)'
+    x = LinRange{Float32}(-pi,pi,100)'
     y = sin.(x)
     loss() = mean(abs2, m(x) .- y)
     Zygote.refresh()
@@ -118,7 +118,7 @@ losses_SLBFGS = map(1:10) do i
     @show i
     Random.seed!(i)
     m = Chain(Dense(1,5,tanh), Dense(5,5,tanh) , Dense(5,1))
-    x = LinRange(-pi,pi,100)'
+    x = LinRange{Float32}(-pi,pi,100)'
     y = sin.(x)
     loss() = mean(abs2, m(x) .- y)
     Zygote.refresh()