diff --git a/toolkit/stable_diffusion_model.py b/toolkit/stable_diffusion_model.py
index a5f59693..35c0a37c 100644
--- a/toolkit/stable_diffusion_model.py
+++ b/toolkit/stable_diffusion_model.py
@@ -1960,7 +1960,8 @@ class StableDiffusion:
         else:
             latents = self.vae.encode(images).latent_dist.sample()
         # latents = self.vae.encode(images, return_dict=False)[0]
-        latents = latents * (self.vae.config['scaling_factor'] - self.vae.config['shift_factor'])
+        shift = self.vae.config['shift_factor'] if self.vae.config['shift_factor'] is not None else 0
+        latents = latents * (self.vae.config['scaling_factor'] - shift)
         latents = latents.to(device, dtype=dtype)
 
         return latents