diff --git a/src/diffusers/pipelines/ddpm/pipeline_ddpm.py b/src/diffusers/pipelines/ddpm/pipeline_ddpm.py
index 093a3cdfe512..3112ef7d5b5d 100644
--- a/src/diffusers/pipelines/ddpm/pipeline_ddpm.py
+++ b/src/diffusers/pipelines/ddpm/pipeline_ddpm.py
@@ -110,6 +110,9 @@ def __call__(
         self.scheduler.set_timesteps(num_inference_steps)
 
         for t in self.progress_bar(self.scheduler.timesteps):
+            # scale_model_input
+            image = self.scheduler.scale_model_input(image, t)
+            
             # 1. predict noise model_output
             model_output = self.unet(image, t).sample