shp2geobuf fails with shapefile containing one feature

[artemp]

shp2geobuf data/polygon.shp > data/polygon.geobuf

/Users/artem/Projects/mapbox/geobuf/encode.js:50
    if (obj.type === 'FeatureCollection') {
           ^
TypeError: Cannot read property 'type' of undefined
    at analyze (/Users/artem/Projects/mapbox/geobuf/encode.js:50:12)
    at encode (/Users/artem/Projects/mapbox/geobuf/encode.js:26:5)
    at /Users/artem/Projects/mapbox/geobuf/bin/shp2geobuf:8:26
    at /Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/index.js:14:23
    at /Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/read.js:26:29
    at notify (/Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/node_modules/queue-async/queue.js:45:26)
    at /Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/node_modules/queue-async/queue.js:35:11
    at /Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/read.js:17:33
    at /Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/index.js:70:27
    at readRecordHeader (/Users/artem/Projects/mapbox/geobuf/node_modules/shapefile/shp.js:34:40)