diff --git a/Gopkg.lock b/Gopkg.lock
index 3d653b30..decb67eb 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -227,7 +227,7 @@
 
 [[projects]]
   branch = "master"
-  digest = "1:157eb52179752d4d88f1049aa6c3e4954d6796af5f6bcd54b5ab40f8637805df"
+  digest = "1:62d3906c154a5fd594c51e434c8d38a3f5ae207f0396bf733fcfbe0ea4796430"
   name = "github.com/tidwall/geojson"
   packages = [
     ".",
@@ -235,7 +235,7 @@
     "geometry",
   ]
   pruneopts = ""
-  revision = "8ff3ef500c61617c9f325603cf40863ca7086a1d"
+  revision = "996bb585989456cda9c8302e89c2fe6e82cc61bf"
 
 [[projects]]
   digest = "1:211773b67c5594aa92b1e8389c59558fa4927614507ea38237265e00c0ba6b81"
diff --git a/vendor/github.com/tidwall/geojson/circle.go b/vendor/github.com/tidwall/geojson/circle.go
index 5a1e5c82..a4df8572 100644
--- a/vendor/github.com/tidwall/geojson/circle.go
+++ b/vendor/github.com/tidwall/geojson/circle.go
@@ -57,7 +57,7 @@ func (g *Circle) AppendJSON(dst []byte) []byte {
 	dst = strconv.AppendFloat(dst, g.center.Y, 'f', -1, 64)
 	dst = append(dst, `]},"properties":{"type":"Circle","radius":`...)
 	dst = strconv.AppendFloat(dst, g.meters, 'f', -1, 64)
-	dst = append(dst, `",radius_units":"m"}}`...)
+	dst = append(dst, `,"radius_units":"m"}}`...)
 	return dst
 }
 
diff --git a/vendor/github.com/tidwall/geojson/circle_test.go b/vendor/github.com/tidwall/geojson/circle_test.go
index 859cd832..0407b26d 100644
--- a/vendor/github.com/tidwall/geojson/circle_test.go
+++ b/vendor/github.com/tidwall/geojson/circle_test.go
@@ -3,6 +3,10 @@ package geojson
 import "testing"
 
 func TestCircle(t *testing.T) {
+	expectJSON(t,
+		`{"type":"Feature","geometry":{"type":"Point","coordinates":[-112,33]},"properties":{"type":"Circle","radius":"5000"}}`,
+		`{"type":"Feature","geometry":{"type":"Point","coordinates":[-112,33]},"properties":{"type":"Circle","radius":5000,"radius_units":"m"}}`,
+	)
 	g, err := Parse(`{
 	"type":"Feature",
 	"geometry":{"type":"Point","coordinates":[-112.2693,33.5123]},  
@@ -14,5 +18,5 @@ func TestCircle(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	println(g.Contains(PO(-112.26, 33.51)))
+	expect(t, g.Contains(PO(-112.26, 33.51)))
 }
diff --git a/vendor/github.com/tidwall/geojson/collection_test.go b/vendor/github.com/tidwall/geojson/collection_test.go
index 0dd99743..0bb379bf 100644
--- a/vendor/github.com/tidwall/geojson/collection_test.go
+++ b/vendor/github.com/tidwall/geojson/collection_test.go
@@ -97,7 +97,7 @@ func TestCollectionBostonSubset(t *testing.T) {
 
 func TestCollectionUSASubset(t *testing.T) {
 	data, err := ioutil.ReadFile("test_files/usa.geojson")
-	if err == nil {
+	if err != nil {
 		fmt.Printf("test_files/usa.geojson missing\n")
 		return
 	}
diff --git a/vendor/github.com/tidwall/geojson/geometry/rect.go b/vendor/github.com/tidwall/geojson/geometry/rect.go
index 8c280d4b..2072222d 100644
--- a/vendor/github.com/tidwall/geojson/geometry/rect.go
+++ b/vendor/github.com/tidwall/geojson/geometry/rect.go
@@ -17,6 +17,11 @@ func (rect Rect) Move(deltaX, deltaY float64) Rect {
 	}
 }
 
+// Index ...
+func (rect Rect) Index() interface{} {
+	return nil
+}
+
 // Clockwise ...
 func (rect Rect) Clockwise() bool {
 	return false
diff --git a/vendor/github.com/tidwall/geojson/geometry/rect_test.go b/vendor/github.com/tidwall/geojson/geometry/rect_test.go
index 1f451ced..7e674c01 100644
--- a/vendor/github.com/tidwall/geojson/geometry/rect_test.go
+++ b/vendor/github.com/tidwall/geojson/geometry/rect_test.go
@@ -21,6 +21,10 @@ func TestRectMove(t *testing.T) {
 	expect(t, R(1, 2, 3, 4).Move(5, 6) == R(6, 8, 8, 10))
 }
 
+func TestRectIndex(t *testing.T) {
+	expect(t, (Rect{}).Index() == nil)
+}
+
 func TestRectNumPoints(t *testing.T) {
 	expect(t, R(0, 0, 10, 10).NumPoints() == 5)
 }
diff --git a/vendor/github.com/tidwall/geojson/geometry/series.go b/vendor/github.com/tidwall/geojson/geometry/series.go
index 24e99ea5..413962e5 100644
--- a/vendor/github.com/tidwall/geojson/geometry/series.go
+++ b/vendor/github.com/tidwall/geojson/geometry/series.go
@@ -24,6 +24,7 @@ type Series interface {
 	PointAt(index int) Point
 	SegmentAt(index int) Segment
 	Search(rect Rect, iter func(seg Segment, index int) bool)
+	Index() interface{}
 }
 
 func seriesCopyPoints(series Series) []Point {
@@ -41,7 +42,7 @@ type baseSeries struct {
 	convex    bool        // points create a convex shape
 	rect      Rect        // minumum bounding rectangle
 	points    []Point     // original points
-	tree      *d2.BoxTree // segment tree
+	tree      *d2.BoxTree // segment tree.
 }
 
 // makeSeries returns a processed baseSeries.
@@ -62,6 +63,14 @@ func makeSeries(points []Point, copyPoints, closed bool, index int) baseSeries {
 	return series
 }
 
+// Index ...
+func (series *baseSeries) Index() interface{} {
+	if series.tree == nil {
+		return nil
+	}
+	return series.tree
+}
+
 // Clockwise ...
 func (series *baseSeries) Clockwise() bool {
 	return series.clockwise
diff --git a/vendor/github.com/tidwall/geojson/geometry/series_test.go b/vendor/github.com/tidwall/geojson/geometry/series_test.go
index fe9989d2..f4344770 100644
--- a/vendor/github.com/tidwall/geojson/geometry/series_test.go
+++ b/vendor/github.com/tidwall/geojson/geometry/series_test.go
@@ -34,6 +34,16 @@ func TestSeriesEmpty(t *testing.T) {
 	expect(t, series2.Empty())
 }
 
+func TestSeriesIndex(t *testing.T) {
+	series := makeSeries(nil, false, false, 0)
+	expect(t, series.Index() == nil)
+	series = makeSeries([]Point{
+		P(0, 0), P(10, 0), P(10, 10), P(0, 10), P(0, 0),
+	}, true, true, 1)
+
+	expect(t, series.Index() != nil)
+}
+
 func TestSeriesClockwise(t *testing.T) {
 	var series baseSeries
 	series = makeSeries([]Point{