diff --git a/Project.toml b/Project.toml
index 785e0390e..8fb1eb6c4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ModelPredictiveControl"
 uuid = "61f9bdb8-6ae4-484a-811f-bbf86720c31c"
 authors = ["Francis Gagnon"]
-version = "1.3.3"
+version = "1.3.4"
 
 [deps]
 ControlSystemsBase = "aaaaaaaa-a6ca-5380-bf3e-84a91bcd477e"
diff --git a/src/model/linmodel.jl b/src/model/linmodel.jl
index 49c26ee40..24f40ba05 100644
--- a/src/model/linmodel.jl
+++ b/src/model/linmodel.jl
@@ -21,7 +21,7 @@ struct LinModel{NT<:Real} <: SimModel{NT}
     yname::Vector{String}
     dname::Vector{String}
     xname::Vector{String}
-    buffer::SimModelBuffer{NT, Nothing}
+    buffer::SimModelBuffer{NT}
     function LinModel{NT}(A, Bu, C, Bd, Dd, Ts) where {NT<:Real}
         A, Bu = to_mat(A, 1, 1), to_mat(Bu, 1, 1)
         nu, nx = size(Bu, 2), size(A, 2)
diff --git a/src/sim_model.jl b/src/sim_model.jl
index b884d7919..3881b47c5 100644
--- a/src/sim_model.jl
+++ b/src/sim_model.jl
@@ -20,73 +20,12 @@ julia> y = model()
 """
 abstract type SimModel{NT<:Real} end
 
-struct JacobianBuffer{
-    NT<:Real, 
-    FX<:Function,
-    FU<:Function,
-    FD<:Function,
-    HX<:Function,
-    HU<:Function,
-    CFX<:ForwardDiff.JacobianConfig,
-    CFU<:ForwardDiff.JacobianConfig,
-    CFD<:ForwardDiff.JacobianConfig,
-    CHU<:ForwardDiff.JacobianConfig,
-    CHX<:ForwardDiff.JacobianConfig
-}
-    xnext::Vector{NT}
-    x::Vector{NT}
-    y::Vector{NT}
-    u::Vector{NT}
-    d::Vector{NT}
-    f_x!::FX
-    f_u!::FU
-    f_d!::FD
-    h_x!::HX
-    h_d!::HU
-    f_x_cfg::CFX
-    f_u_cfg::CFU
-    f_d_cfg::CFD
-    h_x_cfg::CHX
-    h_d_cfg::CHU
-end
-
-"""
-    JacobianBuffer(NT::DataType, f!::Function, h!::Function, nx, nu, ny, nd)
-
-Buffer object for calling `ForwardDiff.jacobian!` on `SimModel` without any allocation.
-"""
-function JacobianBuffer{NT}(
-    f!::Function, h!::Function, nx::Int, nu::Int, ny::Int, nd::Int
-) where NT <: Real 
-    xnext = Vector{NT}(undef, nx)
-    x = Vector{NT}(undef, nx)
-    y = Vector{NT}(undef, ny)
-    u = Vector{NT}(undef, nu)
-    d = Vector{NT}(undef, nd)
-    f_x!(y, x) = f!(y, x, u, d)
-    f_u!(y, u) = f!(y, x, u, d)
-    f_d!(y, d) = f!(y, x, u, d)
-    h_x!(y, x) = h!(y, x, d)
-    h_d!(y, d) = h!(y, x, d)
-    f_x_cfg = ForwardDiff.JacobianConfig(f_x!, xnext, x)
-    f_u_cfg = ForwardDiff.JacobianConfig(f_u!, xnext, u)
-    f_d_cfg = ForwardDiff.JacobianConfig(f_d!, xnext, d)
-    h_x_cfg = ForwardDiff.JacobianConfig(h_x!, y, x)
-    h_d_cfg = ForwardDiff.JacobianConfig(h_d!, y, d)
-    return JacobianBuffer(
-        xnext,      x,          y,          u,          d,
-        f_x!,       f_u!,       f_d!,       h_x!,       h_d!, 
-        f_x_cfg,    f_u_cfg,    f_d_cfg,    h_x_cfg,    h_d_cfg
-    )
-end
-
-struct SimModelBuffer{NT<:Real, JB<:Union{JacobianBuffer, Nothing}}
+struct SimModelBuffer{NT<:Real}
     u::Vector{NT}
     x::Vector{NT}
     y::Vector{NT}
     d::Vector{NT}
     empty::Vector{NT}
-    jacobian::JB
 end
 
 @doc raw"""
@@ -96,15 +35,13 @@ Create a buffer for `SimModel` objects for inputs, states, outputs, and disturba
 
 The buffer is used to store intermediate results during simulation without allocating.
 """
-function SimModelBuffer{NT}(
-    nu::Int, nx::Int, ny::Int, nd::Int, jacobian::JB=nothing
-) where {NT <: Real, JB <: Union{JacobianBuffer, Nothing}}
+function SimModelBuffer{NT}(nu::Int, nx::Int, ny::Int, nd::Int) where {NT <: Real}
     u = Vector{NT}(undef, nu)
     x = Vector{NT}(undef, nx)
     y = Vector{NT}(undef, ny)
     d = Vector{NT}(undef, nd)
     empty = Vector{NT}(undef, 0)
-    return SimModelBuffer{NT, JB}(u, x, y, d, empty, jacobian)
+    return SimModelBuffer{NT}(u, x, y, d, empty)
 end