diff --git a/charms_ceph/utils.py b/charms_ceph/utils.py
index 5dc6ed1..9a88832 100644
--- a/charms_ceph/utils.py
+++ b/charms_ceph/utils.py
@@ -709,7 +709,7 @@ def get_local_osd_ids():
         try:
             dirs = os.listdir(osd_path)
             for osd_dir in dirs:
-                osd_id = osd_dir.split('-')[1]
+                osd_id = osd_dir.split('-')[1] if '-' in osd_dir else ''
                 if (_is_int(osd_id) and
                         filesystem_mounted(os.path.join(
                             os.sep, osd_path, osd_dir)) and
diff --git a/unit_tests/test_osd_upgrade_roll.py b/unit_tests/test_osd_upgrade_roll.py
index 5d553ff..a50bb18 100644
--- a/unit_tests/test_osd_upgrade_roll.py
+++ b/unit_tests/test_osd_upgrade_roll.py
@@ -478,6 +478,21 @@ class UpgradeRollingTestCase(unittest.TestCase):
         self.assertIn(listdir.return_value[0][-1], osds)
         self.assertNotIn(listdir.return_value[1][-1], osds)
 
+    @patch('os.path.exists')
+    @patch('os.listdir')
+    @patch.object(charms_ceph.utils, 'filesystem_mounted')
+    def test_get_osd_ids_unexpected_files(self, fs_mounted, listdir, exists):
+        exists.return_value = True
+        listdir.return_value = [
+            '/var/lib/ceph/osd/ceph-1',
+            '/var/lib/ceph/osd/ceph-2',
+            '/var/lib/ceph/osd/ohno!'
+        ]
+        fs_mounted.side_effect = lambda x: x == listdir.return_value[0]
+        osds = charms_ceph.utils.get_local_osd_ids()
+        self.assertIn(listdir.return_value[0][-1], osds)
+        self.assertNotIn(listdir.return_value[1][-1], osds)
+
 
 """
     @patch.object(charms_ceph.utils, 'log')