diff --git a/niworkflows/interfaces/tests/test_bids.py b/niworkflows/interfaces/tests/test_bids.py
index 01ce1da2939..d531d0a8e6d 100644
--- a/niworkflows/interfaces/tests/test_bids.py
+++ b/niworkflows/interfaces/tests/test_bids.py
@@ -710,7 +710,7 @@ def test_ReadSidecarJSON_connection(testdata_dir, field):
     ('derivatives', 'subjects_dir'),
     [
         (os.getenv('FREESURFER_HOME'), 'subjects'),
-        ('/tmp', os.path.join(os.getenv('FREESURFER_HOME'), 'subjects')),  # noqa: S108
+        ('/tmp', os.path.join(os.getenv('FREESURFER_HOME', ''), 'subjects')),  # noqa: S108
     ],
 )
 def test_fsdir_noaction(derivatives, subjects_dir):