diff --git a/test/test_cep.f90 b/test/test_cep.f90
new file mode 100644
index 00000000..61380c0e
--- /dev/null
+++ b/test/test_cep.f90
@@ -0,0 +1,32 @@
+program main
+   use yaeos
+   use yaeos__equilibria_critical, only: f_cep, f_cep2, df_cep
+   use fixtures_models, only: binary_PR76
+   implicit none
+
+   integer, parameter :: nc=2
+
+   type(CubicEoS) :: model
+   type(EquilibriumState) :: cp
+   real(pr) :: X(nc+4)
+   real(pr) :: a = 0.3
+   real(pr) :: z0(nc) = [1, 0]
+   real(pr) :: zi(nc) = [0, 1]
+   real(pr) :: z(nc)
+
+   integer :: ns=2
+   real(pr) :: s = 0.5
+   real(pr) :: u(nc) = 0.5
+
+   real(pr) :: f(nc+4), df(nc+4, nc+4), df_num(nc+4, nc+4), dx=1e-7
+   integer :: i
+   model = binary_PR76()
+   
+   cp = critical_point(model, z0, zi, spec=spec_CP%a, S=a, max_iters=300)
+
+   X = [0.5_pr, 0.5_pr, log(cp%Vx), log(0.1_pr), log(250._pr), 0.5_pr]
+
+   f = f_cep2(model, X, ns, s, z0, zi, u)
+   df = df_cep(model, X, ns, s, z0, zi, u)
+
+end program
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