diff --git a/geojson/bbox_test.go b/geojson/bbox_test.go
index 7d18d7a..695320d 100644
--- a/geojson/bbox_test.go
+++ b/geojson/bbox_test.go
@@ -1,11 +1,23 @@
 package geojson
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/paulmach/orb"
 )
 
+func TestBBox(t *testing.T) {
+	ls := orb.LineString{{1, 3}, {0, 4}}
+	b := ls.Bound()
+
+	bbox := NewBBox(b)
+	expected := BBox{0, 3, 1, 4}
+	if !reflect.DeepEqual(bbox, expected) {
+		t.Errorf("incorrect result: %v != %v", bbox, expected)
+	}
+}
+
 func TestBBoxValid(t *testing.T) {
 	cases := []struct {
 		name   string
diff --git a/geojson/feature_collection_test.go b/geojson/feature_collection_test.go
index fe2cfe6..ecef31a 100644
--- a/geojson/feature_collection_test.go
+++ b/geojson/feature_collection_test.go
@@ -122,6 +122,55 @@ func TestUnmarshalFeatureCollection(t *testing.T) {
 	}
 }
 
+func TestUnmarshalFeatureCollection_errors(t *testing.T) {
+	t.Run("type not a string", func(t *testing.T) {
+		rawJSON := `
+		  { "type": { "foo":"bar" },
+		    "features": [
+		      { "type": "Feature",
+		        "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
+		        "properties": {"prop0": "value0"}
+		      }
+		     ]
+		  }`
+
+		_, err := UnmarshalFeatureCollection([]byte(rawJSON))
+		if _, ok := err.(*json.UnmarshalTypeError); !ok {
+			t.Fatalf("wrong error: %T: %v", err, err)
+		}
+	})
+
+	t.Run("bbox invalid", func(t *testing.T) {
+		rawJSON := `
+		  { "type": "FeatureCollection",
+		    "bbox": { "foo":"bar" },
+		    "features": [
+		      { "type": "Feature",
+		        "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
+		        "properties": {"prop0": "value0"}
+		      }
+		     ]
+		  }`
+
+		_, err := UnmarshalFeatureCollection([]byte(rawJSON))
+		if _, ok := err.(*json.UnmarshalTypeError); !ok {
+			t.Fatalf("wrong error: %T: %v", err, err)
+		}
+	})
+
+	t.Run("features invalid", func(t *testing.T) {
+		rawJSON := `
+		  { "type": "FeatureCollection",
+		    "features": { "foo":"bar" }
+		  }`
+
+		_, err := UnmarshalFeatureCollection([]byte(rawJSON))
+		if _, ok := err.(*json.UnmarshalTypeError); !ok {
+			t.Fatalf("wrong error: %T: %v", err, err)
+		}
+	})
+}
+
 func TestFeatureCollectionMarshalJSON(t *testing.T) {
 	fc := NewFeatureCollection()
 	blob, err := fc.MarshalJSON()