diff --git a/phobos/data/defaults.json b/phobos/data/defaults.json
index c5ba47db..c6d42244 100644
--- a/phobos/data/defaults.json
+++ b/phobos/data/defaults.json
@@ -40,7 +40,8 @@
         "opening_width": 90,
         "depth_image": true,
         "show_cam": false,
-        "frame_offset": 1
+        "frame_offset": 1,
+        "topic": ""
       }
     },
     "IMU": {