diff --git a/docling/models/page_preprocessing_model.py b/docling/models/page_preprocessing_model.py
index 438114d8..52f92129 100644
--- a/docling/models/page_preprocessing_model.py
+++ b/docling/models/page_preprocessing_model.py
@@ -1,4 +1,4 @@
-from typing import Iterable
+from typing import Iterable, Optional
 
 from PIL import ImageDraw
 from pydantic import BaseModel
@@ -8,7 +8,7 @@ from docling.models.abstract_model import AbstractPageModel
 
 
 class PagePreprocessingOptions(BaseModel):
-    images_scale: float
+    images_scale: Optional[float]
 
 
 class PagePreprocessingModel(AbstractPageModel):
diff --git a/docling/pipeline/standard_pdf_model_pipeline.py b/docling/pipeline/standard_pdf_model_pipeline.py
index cba8609b..53558579 100644
--- a/docling/pipeline/standard_pdf_model_pipeline.py
+++ b/docling/pipeline/standard_pdf_model_pipeline.py
@@ -47,7 +47,7 @@ class StandardPdfModelPipeline(PaginatedModelPipeline):
             )
         )
 
-        if ocr_model := self.get_ocr_model() is None:
+        if (ocr_model := self.get_ocr_model()) is None:
             raise RuntimeError(
                 f"The specified OCR kind is not supported: {pipeline_options.ocr_options.kind}."
             )