diff --git a/src/ocrmypdf/_sync.py b/src/ocrmypdf/_sync.py
index 6a9a85a8..1c971484 100644
--- a/src/ocrmypdf/_sync.py
+++ b/src/ocrmypdf/_sync.py
@@ -206,7 +206,7 @@ def exec_page_sync(page_context: PageContext) -> PageResult:
         filtered_image = page_context.plugin_manager.hook.filter_page_image(
             page=page_context, image_filename=visible_image_out
         )
-        if filtered_image:
+        if filtered_image is not None:  # None if no hook is present
             visible_image_out = filtered_image
         pdf_page_from_image_out = create_pdf_page_from_image(
             visible_image_out, page_context, orientation_correction
diff --git a/src/ocrmypdf/pluginspec.py b/src/ocrmypdf/pluginspec.py
index c3298e4c..dfa2e3ea 100644
--- a/src/ocrmypdf/pluginspec.py
+++ b/src/ocrmypdf/pluginspec.py
@@ -278,10 +278,6 @@ def filter_page_image(page: PageContext, image_filename: Path) -> Path:
     will occur. The return value should be a path to a file in the same folder
     as ``image_filename``.
 
-    Implementation detail: If the value returned is falsy, OCRmyPDF will ignore
-    the return value and assume the input file was unmodified. This is deprecated.
-    To leave the image unmodified, ``image_filename`` should be returned.
-
     Note:
         This hook will be called from child processes. Modifying global state
         will not affect the main process or other child processes.