1 files changed, 3 insertions, 0 deletions

diff --git a/pipelines/stable_diffusion/vlpn_stable_diffusion.py b/pipelines/stable_diffusion/vlpn_stable_diffusion.py
index 3da0169..e90528d 100644
--- a/pipelines/stable_diffusion/vlpn_stable_diffusion.py
+++ b/pipelines/stable_diffusion/vlpn_stable_diffusion.py
@@ -159,6 +159,9 @@ class VlpnStableDiffusion(DiffusionPipeline):
 
         batch_size = len(prompt)
 
+        if negative_prompt is None:
+            negative_prompt = ""
+
         if isinstance(negative_prompt, str):
             negative_prompt = [negative_prompt] * batch_size