diff --git a/src/diffusers/modular_pipelines/modular_pipeline.py b/src/diffusers/modular_pipelines/modular_pipeline.py
index 99e12749dd..8a05cce209 100644
--- a/src/diffusers/modular_pipelines/modular_pipeline.py
+++ b/src/diffusers/modular_pipelines/modular_pipeline.py
@@ -800,7 +800,7 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
 
     @property
     def model_name(self):
-        return next(iter(self.sub_blocks.values())).model_name
+        return next((block.model_name for block in self.sub_blocks.values() if block.model_name is not None), None)
 
     @property
     def expected_components(self):