diff --git a/unidock_tools/tests/ut/proprep/test_receptor_processor.py b/unidock_tools/tests/ut/proprep/test_receptor_processor.py
index cd70e5f..efb40da 100644
--- a/unidock_tools/tests/ut/proprep/test_receptor_processor.py
+++ b/unidock_tools/tests/ut/proprep/test_receptor_processor.py
@@ -11,7 +11,7 @@ def test_receptor_preprocessor(pdb_file):
     from unidock_tools.modules.protein_prep import receptor_preprocessor
     # Create a temporary working directory
     with tempfile.TemporaryDirectory() as temp_dir:
-        protein_pdbqt_file_name = receptor_preprocessor(pdb_file, prepared_hydrogen=True, working_dir_name=temp_dir)
+        protein_pdbqt_file_name, ad4_maps_prefix = receptor_preprocessor(pdb_file, prepared_hydrogen=True, working_dir_name=temp_dir)
         # Assert that the generated PDBQT file exists
         assert os.path.exists(protein_pdbqt_file_name)