diff --git a/Project.toml b/Project.toml
index 63488ed..788dda6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,12 +1,14 @@
 name = "RadiationSpectra"
 uuid = "4f207c7e-01da-51d7-a1a0-c8c06dd1d883"
-version = "0.5.12"
+version = "0.5.13"
 
 [deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
 DensityInterface = "b429d917-457f-4dbc-8f4c-0cc954292b1d"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 EmpiricalDistributions = "0bbb1fad-0f24-45fe-94a4-415852c5cc3b"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 IntervalSets = "8197267c-284f-5f27-9208-e0e47529a953"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 NamedTupleTools = "d9ec5142-1e00-5aa0-9d6a-321866360f50"
@@ -22,14 +24,16 @@ StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 ValueShapes = "136a8f8c-c49b-4edb-8b98-f3d64d48be8f"
 
 [compat]
+ADTypes = "1.11"
 DelimitedFiles = "1"
 DensityInterface = "0.4"
 Distributions = "0.25"
 EmpiricalDistributions = "0.3"
+ForwardDiff = "0.10, 1"
 IntervalSets = "0.5, 0.6, 0.7"
 LinearAlgebra = "1"
 NamedTupleTools = "0.13, 0.14"
-Optim = "1"
+Optim = "1.13, 2"
 Random123 = "1"
 RecipesBase = "1"
 Requires = "1"
diff --git a/src/AutoCalibration/AutoCalibration.jl b/src/AutoCalibration/AutoCalibration.jl
index f7cc476..d6ba76f 100644
--- a/src/AutoCalibration/AutoCalibration.jl
+++ b/src/AutoCalibration/AutoCalibration.jl
@@ -192,7 +192,7 @@ function determine_calibration_constant_through_peak_fitting(h::Histogram{<:Real
         _linear_function_fixed_offset_at_zero, 
         Float64[0], Float64[Inf], Float64[c_pre], 
         Fminbox(BFGS()); 
-        autodiff=:forward )
+        autodiff=AutoForwardDiff() )
     
     c = opt_result.minimizer[1]
 
diff --git a/src/RadiationSpectra.jl b/src/RadiationSpectra.jl
index 65bd0dd..7011412 100644
--- a/src/RadiationSpectra.jl
+++ b/src/RadiationSpectra.jl
@@ -9,8 +9,10 @@ module RadiationSpectra
     using LinearAlgebra
     using Statistics
 
+    using ADTypes: AutoForwardDiff
     using DensityInterface
     using EmpiricalDistributions
+    using ForwardDiff
     using IntervalSets
     using NamedTupleTools
     using Optim
diff --git a/src/UnivariateFit.jl b/src/UnivariateFit.jl
index ddfd249..4f07f45 100644
--- a/src/UnivariateFit.jl
+++ b/src/UnivariateFit.jl
@@ -61,7 +61,7 @@ function opt_fit(DT::Type{<:UvSpectrumDensity}, h::Histogram{<:Any, 1},
         return -DensityInterface.logdensityof(d, x)
     end
     opt_result = Optim.optimize( f, promote(lower_bounds, upper_bounds, p0)..., 
-        Fminbox(BFGS()); autodiff=:forward )
+        Fminbox(BFGS()); autodiff=AutoForwardDiff() )
     # return opt_result.minimizer, opt_result
     return DT(_par_in_input_form(parshape(opt_result.minimizer))), opt_result
 end