diff --git a/eynollah/eynollah/processor.py b/eynollah/eynollah/processor.py
index 8f34b1b..a03c9c3 100644
--- a/eynollah/eynollah/processor.py
+++ b/eynollah/eynollah/processor.py
@@ -59,7 +59,7 @@ class EynollahProcessor(Processor):
                 'override_dpi': self.parameter['dpi'],
                 'logger': LOG,
                 'pcgts': pcgts,
-                'image_filename': image_filename
+                'image_filename': str(image_filename)
                 }
             Eynollah(**eynollah_kwargs).run()
             file_id = make_file_id(input_file, self.output_file_grp)