diff --git a/comfy/k_diffusion/sampling.py b/comfy/k_diffusion/sampling.py
index a8293162..2838b50c 100644
--- a/comfy/k_diffusion/sampling.py
+++ b/comfy/k_diffusion/sampling.py
@@ -317,7 +317,6 @@ def sample_dpm_2_ancestral_RF(model, x, sigmas, extra_args=None, callback=None,
     s_in = x.new_ones([x.shape[0]])
     for i in trange(len(sigmas) - 1, disable=disable):
         denoised = model(x, sigmas[i] * s_in, **extra_args)
-        sigma_down, sigma_up = get_ancestral_step(sigmas[i], sigmas[i + 1], eta=eta)
         downstep_ratio = 1 + (sigmas[i+1]/sigmas[i] - 1) * eta
         sigma_down = sigmas[i+1] * downstep_ratio
         alpha_ip1 = 1 - sigmas[i+1]