diff --git a/docling/pipeline/threaded_standard_pdf_pipeline.py b/docling/pipeline/threaded_standard_pdf_pipeline.py
index d3ea2f82..6c734bd9 100644
--- a/docling/pipeline/threaded_standard_pdf_pipeline.py
+++ b/docling/pipeline/threaded_standard_pdf_pipeline.py
@@ -527,6 +527,9 @@ class ThreadedStandardPdfPipeline(BasePipeline):
             for st in ctx.stages:
                 st.stop()
             ctx.output_queue.close()
+
+            if conv_res.input._backend is not None:
+                conv_res.input._backend.unload()
         return conv_res
 
     # -------------------------------------------------------------- feed_pages
diff --git a/tests/test_threaded_pipeline.py b/tests/test_threaded_pipeline.py
index b431c508..bc6fb4e5 100644
--- a/tests/test_threaded_pipeline.py
+++ b/tests/test_threaded_pipeline.py
@@ -18,7 +18,7 @@ from docling.pipeline.threaded_standard_pdf_pipeline import ThreadedStandardPdfP
 
 def test_threaded_pipeline_multiple_documents():
     """Test threaded pipeline with multiple documents and compare with standard pipeline"""
-    test_files = [
+    test_files = [str(f) for f in Path("tests/data/pdf").rglob("*.pdf")] or [
         "tests/data/pdf/2203.01017v2.pdf",
         "tests/data/pdf/2206.01062.pdf",
         "tests/data/pdf/2305.03393v1.pdf",