diff --git a/ref_test.go b/ref_test.go
new file mode 100644
index 0000000..06d3cd1
--- /dev/null
+++ b/ref_test.go
@@ -0,0 +1,41 @@
+package goref_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/korfuri/goref"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestJSON(t *testing.T) {
+	correct := "{\"from\":{\"position\":{\"filename\":\"x/foo.go\",\"start_line\":42,\"end_line\":42,\"end_col\":10},\"package\":\"path/to/x\",\"ident\":\"foo\"},\"to\":{\"position\":{\"filename\":\"y/bar.go\",\"start_line\":314,\"start_col\":11,\"end_line\":314,\"end_col\":14},\"package\":\"path/to/y\",\"ident\":\"bar\"}}"
+	r := goref.Ref{
+		RefType: goref.Instantiation,
+		FromPosition: goref.Position{
+			File: "x/foo.go",
+			PosC: 0,
+			PosL: 42,
+			EndC: 10,
+			EndL: 42,
+		},
+		ToPosition: goref.Position{
+			File: "y/bar.go",
+			PosC: 11,
+			PosL: 314,
+			EndC: 14,
+			EndL: 314,
+		},
+		FromIdent: "foo",
+		ToIdent:   "bar",
+		FromPackage: &goref.Package{
+			Path: "path/to/x",
+		},
+		ToPackage: &goref.Package{
+			Path: "path/to/y",
+		},
+	}
+	j, err := json.Marshal(r)
+	assert.NoError(t, err)
+	assert.Equal(t, correct, string(j))
+}