diff --git a/src/integration.jl b/src/integration.jl
index 8ae65cb3..7365894a 100644
--- a/src/integration.jl
+++ b/src/integration.jl
@@ -24,6 +24,31 @@ function discrete_dynamics(::Type{RK4}, model::AbstractModel, x::SVector, u::SVe
 	x + (k1 + 4k2 + 4k3 + k4)/6
 end
 
+function discrete_dynamics(::Type{RK8}, model::AbstractModel, y::SVector{N,T}, u::SVector{M,T},t, dt::T) where {N,M,T}
+	α    = @SVector [ 2/27, 1/9, 1/6, 5/12, .5, 5/6, 1/6, 2/3, 1/3, 1, 0, 1 ];
+	β    = @SMatrix [  2/27       0       0      0        0         0       0         0     0      0     0 0 0;
+	1/36       1/12    0      0        0         0       0         0     0      0     0 0 0;
+	1/24       0       1/8    0        0         0       0         0     0      0     0 0 0;
+	5/12       0       -25/16 25/16    0         0       0         0     0      0     0 0 0;
+	.05        0       0      .25      .2        0       0         0     0      0     0 0 0;
+	-25/108    0       0      125/108  -65/27    125/54  0         0     0      0     0 0 0;
+	31/300     0       0      0        61/225    -2/9    13/900    0     0      0     0 0 0;
+	2          0       0      -53/6    704/45    -107/9  67/90     3     0      0     0 0 0;
+	-91/108    0       0      23/108   -976/135  311/54  -19/60    17/6  -1/12  0     0 0 0;
+	2383/4100  0       0      -341/164 4496/1025 -301/82 2133/4100 45/82 45/164 18/41 0 0 0;
+	3/205      0       0      0        0         -6/41   -3/205    -3/41 3/41   6/41  0 0 0;
+	-1777/4100 0       0      -341/164 4496/1025 -289/82 2193/4100 51/82 33/164 12/41 0 1 0]
+	χ     = @SVector[0, 0, 0, 0, 0, 34/105, 9/35, 9/35, 9/280, 9/280, 0, 41/840, 41/840 ]; # Difference between two bottom layers of butcher tableau
+
+	f = y*zeros(eltype(y),1,13)
+
+	f[:,1] = dynamics(model,y,u,t)
+	for j = 1:12
+	f[:,j+1] = dynamics(model, y + dt*f*β[j,:],u,t + α[j]*dt)
+	end
+	return y + dt*f*χ
+end
+
 
 ############################################################################################
 #                                  EXPLICIT METHODS 								       #
diff --git a/src/model.jl b/src/model.jl
index a6ddcc0b..95094270 100644
--- a/src/model.jl
+++ b/src/model.jl
@@ -62,13 +62,16 @@ abstract type Implicit <: QuadratureRule end
 "Integration rules of the form x′ = f(x,u,x′,u′), where x′,u′ are the states and controls at the next time step."
 abstract type Explicit <: QuadratureRule end
 
-"Fourth-order Runge-Kutta method with zero-order-old on the controls"
+"Eigth-order Runge-Kutta method"
+abstract type RK8 <: Implicit end
+
+"Fourth-order Runge-Kutta method with zero-order-hold on the controls"
 abstract type RK4 <: Implicit end
 
-"Second-order Runge-Kutta method with zero-order-old on the controls"
+"Second-order Runge-Kutta method with zero-order-hold on the controls"
 abstract type RK3 <: Implicit end
 
-"Second-order Runge-Kutta method with zero-order-old on the controls"
+"Second-order Runge-Kutta method with zero-order-hold on the controls"
 abstract type RK2 <: Implicit end
 
 "Third-order Runge-Kutta method with first-order-hold on the controls"