diff --git a/test/index.js b/test/index.js
index f104c49..c73aedf 100644
--- a/test/index.js
+++ b/test/index.js
@@ -2,8 +2,9 @@ import test from 'ava'
 import {findAndReplace, findAndReplaceIf} from '../dist/index.cjs'
 
 test('findAndReplace', t => {
-  let res
-  res = findAndReplace({a: {b: {c: 'a'}}}, 'a', 'b')
+  let res, ori
+  ori = {a: {b: {c: 'a'}}}
+  res = findAndReplace(ori, 'a', 'b')
   t.deepEqual(res, {a: {b: {c: 'b'}}})
   res = findAndReplace('_', 'a', 'b')
   t.is(res, '_')
@@ -11,6 +12,31 @@ test('findAndReplace', t => {
   t.is(res, 'b')
 })
 
+test('findAndReplace does not modify objects', t => {
+  let res, ori
+  ori = {a: {b: {c: 'a'}, d: 1}}
+  res = findAndReplace(ori, 'a', 'b')
+  t.deepEqual(res, {a: {b: {c: 'b'}, d: 1}})
+  t.deepEqual(ori, {a: {b: {c: 'a'}, d: 1}})
+  res.a.b = 1
+  t.deepEqual(res, {a: {b: 1, d: 1}})
+  t.deepEqual(ori, {a: {b: {c: 'a'}, d: 1}})
+  res.a.d = 2
+  t.deepEqual(res, {a: {b: 1, d: 2}})
+  t.deepEqual(ori, {a: {b: {c: 'a'}, d: 1}})
+  ori.a.d = 3
+  t.deepEqual(res, {a: {b: 1, d: 2}})
+  t.deepEqual(ori, {a: {b: {c: 'a'}, d: 3}})
+})
+
+test('findAndReplace does not work with objects', t => {
+  let res, ori
+  ori = {a: {b: {c: 'a'}}}
+  res = findAndReplace(ori, {c: 'a'}, {c: 'b'})
+  t.deepEqual(res, {a: {b: {c: 'a'}}})
+  t.deepEqual(ori, {a: {b: {c: 'a'}}})
+})
+
 test('findAndReplaceIf', t => {
   let res
   function checkFn (foundVal) {