diff --git a/comfy/extra_samplers/uni_pc.py b/comfy/extra_samplers/uni_pc.py
index 7eaf6ff6..7e88bb9f 100644
--- a/comfy/extra_samplers/uni_pc.py
+++ b/comfy/extra_samplers/uni_pc.py
@@ -688,7 +688,7 @@ class UniPC:
                 x_t = x_t_ - expand_dims(alpha_t * B_h, dims) * (corr_res + rhos_c[-1] * D1_t)
         else:
             x_t_ = (
-                expand_dims(torch.exp(log_alpha_t - log_alpha_prev_0), dimss) * x
+                expand_dims(torch.exp(log_alpha_t - log_alpha_prev_0), dims) * x
                 - expand_dims(sigma_t * h_phi_1, dims) * model_prev_0
             )
             if x_t is None: