diff --git a/benchmark/index.js b/benchmark/index.js
index c64ea20a..2a5c4887 100644
--- a/benchmark/index.js
+++ b/benchmark/index.js
@@ -24,8 +24,6 @@ const obj = {
 	set: new Set([1, 2, 3]),
 	xss: '</script><script>alert("XSS")</script>',
 };
-
-// circular references are not supported by tupleson
 obj.self = obj;
 
 const tson = createTson({
diff --git a/src/index.test.ts b/src/index.test.ts
index caebe3bd..5ca36fe2 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -52,6 +52,8 @@ test("back-reference: circular object reference", () => {
 	const res = t.parse(str);
 
 	expect(res).toEqual(expected);
+	expect(res).toBe(res["a"]);
+	expect(res["b"]).toBe(res["a"]);
 });
 
 test("back-reference: circular array reference", () => {
@@ -67,6 +69,8 @@ test("back-reference: circular array reference", () => {
 	const res = t.parse(str);
 
 	expect(res).toEqual(expected);
+	expect(res).toBe(res[0]);
+	expect(res[1]).toBe(res[0]);
 });
 
 test("back-reference: non-circular complex reference", () => {
@@ -83,6 +87,7 @@ test("back-reference: non-circular complex reference", () => {
 	const str = t.stringify(expected);
 	const res = t.parse(str);
 
+	expect(res).toEqual(expected);
 	expect(res["b"]).toBe(res["a"]);
 	expect(res["d"]).toBe(res["c"]);
 });