diff --git a/Project.toml b/Project.toml
index 95dbf0d..861e8fa 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "DormandPrince"
 uuid = "5e45e72d-22b8-4dd0-9c8b-f96714864bcd"
 authors = ["John Long<jlong@quera.com>", "Phillip Weinberg<pweinberg@quera.com>"]
-version = "0.2.0"
+version = "0.3.0"
 
 [deps]
 
diff --git a/src/interface.jl b/src/interface.jl
index 7099c5b..69a7f28 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -12,7 +12,7 @@ function Base.iterate(solver_iter::SolverIterator)
     # integrate to first time
     integrate(solver_iter.solver, first(solver_iter.times))
     # return value and index which is the state
-    return (solver_iter.times[1], solver_iter.solver.y), 2    
+    return (solver_iter.times[1], get_current_state(solver_iter.solver)), 2    
 end
 
 # gets the next (t,y), return index+! which is the updated state
@@ -21,7 +21,7 @@ function Base.iterate(solver_iter::SolverIterator, index::Int)
     # integrate to next time
     integrate(solver_iter.solver, solver_iter.times[index])
     # return time and state
-    return (solver_iter.times[index], solver_iter.solver.y), index+1
+    return (solver_iter.times[index], get_current_state(solver_iter.solver)), index+1
 end
 
 # 3 modes of operation for integrate
@@ -29,6 +29,7 @@ end
 # 2. integrate(solver, times) -> iterator
 # 3. integrate(callback, solver, times) -> vector of states with callback applied
 
+get_current_state(::AbstractDPSolver) = error("not implemented")
 integrate(solver::AbstractDPSolver{T}, times::AbstractVector{T}) where {T <: Real} = SolverIterator(solver, times)
 
 function integrate(callback, solver::AbstractDPSolver{T}, times::AbstractVector{T}; sort_times::Bool = true) where {T <: Real}
@@ -37,7 +38,7 @@ function integrate(callback, solver::AbstractDPSolver{T}, times::AbstractVector{
     result = []
     for time in times
         integrate(solver, time)
-        push!(result, callback(time, solver.y))
+        push!(result, callback(time, get_current_state(solver)))
     end
 
     return result
diff --git a/src/types.jl b/src/types.jl
index 1ad85e2..45d9983 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -213,3 +213,5 @@ function DP8Solver(
     DP8Solver(f, x, y, k1, k2, k3, k4, k5, k6, k7, k8, k9, k10, y1;kw...)
 end
 
+get_current_state(solver::DP5Solver) = solver.y
+get_current_state(solver::DP8Solver) = solver.y
\ No newline at end of file