diff --git a/test/ext/CoupledSDEsBaisin.jl b/test/ext/CoupledSDEsBaisin.jl
index 9ed60d72..a8dcd721 100644
--- a/test/ext/CoupledSDEsBaisin.jl
+++ b/test/ext/CoupledSDEsBaisin.jl
@@ -2,7 +2,7 @@
     using Attractors, ChaosTools
     # Define systems
     g = diag_noise_function(0.215)
-    system = CoupledSDEs(fitzhugh_nagumo, g, [2.0, 0.1], [0.1, 3.0, 1.0, 1.0, 1.0, 0.0])
+    system = CoupledSDEs(CT.fitzhugh_nagumo, g, [2.0, 0.1], [0.1, 3.0, 1.0, 1.0, 1.0, 0.0])
 
     # Set up domain
     A, B, C = [0.0, 0.0], [1.0, 0.0], [0.0, 1.0]
diff --git a/test/largedeviations/MAM.jl b/test/largedeviations/MAM.jl
index 7509c034..75dfb5b5 100644
--- a/test/largedeviations/MAM.jl
+++ b/test/largedeviations/MAM.jl
@@ -1,6 +1,6 @@
 @testset "MAM FitzHugh-Nagumo" begin
     p = [0.1, 3, 1, 1, 1, 0]
-    fhn = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(0.1), zeros(2), p)
+    fhn = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(0.1), zeros(2), p)
     x_i = SA[sqrt(2 / 3), sqrt(2 / 27)]
     x_f = SA[0.001, 0.0]
     N, T = 200, 2.0
diff --git a/test/largedeviations/action_fhn.jl b/test/largedeviations/action_fhn.jl
index a50afb43..d3251bc0 100644
--- a/test/largedeviations/action_fhn.jl
+++ b/test/largedeviations/action_fhn.jl
@@ -4,7 +4,7 @@ Random.seed!(SEED)
 # System setup - FitzHugh-Nagumo model
 p = [1.0, 3.0, 1.0, 1.0, 1.0, 0.0] # Parameters (ϵ, β, α, γ, κ, I)
 σ = 0.215 # noise strength
-sys = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(σ), zeros(2), p; seed=SEED)
+sys = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(σ), zeros(2), p; seed=SEED)
 
 A = inv(CT.covariance_matrix(sys))
 T, N = 2.0, 100
diff --git a/test/largedeviations/gMAM.jl b/test/largedeviations/gMAM.jl
index e6140fe7..c5478e64 100644
--- a/test/largedeviations/gMAM.jl
+++ b/test/largedeviations/gMAM.jl
@@ -1,6 +1,6 @@
 @testset "gMAM FitzHugh-Nagumo" begin
     p = [0.1, 3, 1, 1, 1, 0]
-    fhn = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(0.1), zeros(2), p)
+    fhn = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(0.1), zeros(2), p)
     x_i = SA[sqrt(2 / 3), sqrt(2 / 27)]
     x_f = SA[0.001, 0.0]
     N = 100
diff --git a/test/trajactories/simulate.jl b/test/trajactories/simulate.jl
index 4b006bcb..6869ffe3 100644
--- a/test/trajactories/simulate.jl
+++ b/test/trajactories/simulate.jl
@@ -3,9 +3,9 @@
     p = [0.1, 3.0, 1.0, 1.0, 1.0, 0.0] # Parameters (ϵ, β, α, γ, κ, I)
     σ = 0.1
     # Simulate
-    sys = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(σ), SA[1.0, 0.0], p)
+    sys = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(σ), SA[1.0, 0.0], p)
     traj = trajectory(sys, 10)
-    sys = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(σ), SA[1.0, 0.0], p)
+    sys = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(σ), SA[1.0, 0.0], p)
     sim = simulate(sys, 10)
     @test traj[1][1, 1] == 1.0
     @test sim.u[1][1] == 1.0
diff --git a/test/trajactories/transition.jl b/test/trajactories/transition.jl
index 1f36c8af..41cf3df8 100644
--- a/test/trajactories/transition.jl
+++ b/test/trajactories/transition.jl
@@ -7,7 +7,7 @@
     σ = 0.215 # noise strength
 
     # CoupledSDEs
-    sys = CoupledSDEs(fitzhugh_nagumo, diag_noise_function(σ), zeros(2), p; seed=SEED)
+    sys = CoupledSDEs(CT.fitzhugh_nagumo, diag_noise_function(σ), zeros(2), p; seed=SEED)
 
     fp1 = [0.816, 0.272]
     fp2 = [-0.816, -0.272]