diff --git a/src/SimpleDiffEq.jl b/src/SimpleDiffEq.jl
index 6299574..be4af2a 100644
--- a/src/SimpleDiffEq.jl
+++ b/src/SimpleDiffEq.jl
@@ -6,6 +6,7 @@ using Reexport, MuladdMacro
 @reexport using DiffEqBase
 using StaticArrays
 using RecursiveArrayTools
+const ^ = DiffEqBase.fastpow
 
 @inline _copy(a::SArray) = a
 @inline _copy(a) = copy(a)
diff --git a/src/tsit5/atsit5.jl b/src/tsit5/atsit5.jl
index f3b61c5..33e5c57 100644
--- a/src/tsit5/atsit5.jl
+++ b/src/tsit5/atsit5.jl
@@ -52,10 +52,10 @@ function DiffEqBase.__init(prob::ODEProblem,alg::SimpleATsit5;
                    internalnorm)
 end
 
-function DiffEqBase.__solve(prob::ODEProblem,alg::SimpleATsit5;
+function DiffEqBase.__solve(prob::ODEProblem,alg::SimpleATsit5,args...;
                           dt = 0.1, saveat = nothing, save_everystep = true,
                           abstol = 1e-6, reltol = 1e-3,
-                          internalnorm = DiffEqBase.ODE_DEFAULT_NORM)
+                          internalnorm = DiffEqBase.ODE_DEFAULT_NORM,kwargs...)
   u0 = prob.u0
   tspan = prob.tspan
   ts = Vector{eltype(dt)}(undef,1)
@@ -78,6 +78,7 @@ function DiffEqBase.__solve(prob::ODEProblem,alg::SimpleATsit5;
   integ = simpleatsit5_init(prob.f,DiffEqBase.isinplace(prob),prob.u0,
                             tspan[1], tspan[2], dt, prob.p, abstol, reltol, internalnorm)
   # FSAL
+  cur_t = 1
   while integ.t < tspan[2]
     step!(integ)
     if saveat === nothing && save_everystep
@@ -96,8 +97,8 @@ function DiffEqBase.__solve(prob::ODEProblem,alg::SimpleATsit5;
   end
 
   if saveat === nothing && !save_everystep
-      push!(us,recursivecopy(u))
-      push!(ts,t)
+      push!(us,recursivecopy(integ.u))
+      push!(ts,integ.t)
   end
 
   sol = DiffEqBase.build_solution(prob,alg,ts,us,