diff --git a/pyproject.toml b/pyproject.toml
index 07ed8bd..bbf13bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "digiflow"
-version = "3.9.1"
+version = "3.9.2"
 description = "Father's Little Digitization Workflow Helper"
 readme = "README.md"
 requires-python = ">=3.8"
diff --git a/src/digiflow/digiflow_metadata.py b/src/digiflow/digiflow_metadata.py
index 3116b64..7150b1b 100644
--- a/src/digiflow/digiflow_metadata.py
+++ b/src/digiflow/digiflow_metadata.py
@@ -320,7 +320,8 @@ def contains_group(self, group: 'str|List[str]') -> bool:
         if isinstance(group, list):
             return any(self.tree.findall(PATTERN_FILEGROUP_USE.format(g), XMLNS)
                        for g in group)
-        return self.tree.findall(PATTERN_FILEGROUP_USE.format(group), XMLNS) > 0
+        _fgroups = self.tree.findall(PATTERN_FILEGROUP_USE.format(group), XMLNS)
+        return len(_fgroups) > 0
 
     def clear_filegroups(self, black_list=None):
         """Clear file Groups by blacklist"""
diff --git a/tests/test_digiflow_metadata.py b/tests/test_digiflow_metadata.py
index 3f3a971..4f0a3e1 100644
--- a/tests/test_digiflow_metadata.py
+++ b/tests/test_digiflow_metadata.py
@@ -786,3 +786,20 @@ def test_metsreader_kitodo2_mena_periodical_volume_dmd_id():
 
     # assert
     assert mets_reader.dmd_id == 'DMDLOG_0001'
+
+
+def test_metadata_processor_contains_single_fgroup():
+    """Ensure behavior for passing single str arg
+    Bugfix: 
+    TypeError: '>' not supported between instances of 'list' and 'int'
+    """
+
+    _proc = MetsProcessor(TEST_RES / 'k2_mets_morbio_1748529021.xml')
+    assert _proc.contains_group('MAX')
+
+
+def test_metadata_processor_contains_multiple_fgroup():
+    """Ensure behavior for passing list args"""
+
+    _proc = MetsProcessor(TEST_RES / 'k2_mets_morbio_1748529021.xml')
+    assert _proc.contains_group(['MAX'])