diff --git a/frigate/timeline.py b/frigate/timeline.py
index f8d341660..8e6aedc67 100644
--- a/frigate/timeline.py
+++ b/frigate/timeline.py
@@ -142,11 +142,14 @@ class TimelineProcessor(threading.Thread):
                 timeline_entry[Timeline.data]["attribute"] = list(
                     event_data["attributes"].keys()
                 )[0]
-                timeline_entry[Timeline.data]["attribute_box"] = to_relative_box(
-                    camera_config.detect.width,
-                    camera_config.detect.height,
-                    event_data["current_attributes"][0]["box"],
-                )
+
+                if len(event_data["current_attributes"]) > 0:
+                    timeline_entry[Timeline.data]["attribute_box"] = to_relative_box(
+                        camera_config.detect.width,
+                        camera_config.detect.height,
+                        event_data["current_attributes"][0]["box"],
+                    )
+
                 save = True
         elif event_type == EventStateEnum.end:
             timeline_entry[Timeline.class_type] = "gone"