diff --git a/.eslintrc.cjs b/.eslintrc.cjs
new file mode 100644
index 0000000..fb3d960
--- /dev/null
+++ b/.eslintrc.cjs
@@ -0,0 +1,16 @@
+"use strict";
+module.exports = {
+  // We tried to stick to ES5 compat for browsers (#44), but eslint can't handle that with modules.
+  // However, it is enforced for the dist/ directory, which just gets a cjs-ify'd version of the lib.
+  parserOptions: { ecmaVersion: 6, sourceType: 'module' },
+  env: {
+    node: true,
+    browser: true,
+  },
+  extends: ["eslint:recommended", "plugin:prettier/recommended"],
+  rules: {
+    "prefer-const": "error",
+    strict: "error",
+    eqeqeq: "error",
+  },
+};
diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index fa1b084..ce613c4 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -20,7 +20,6 @@ jobs:
         node-version: ${{ matrix.node-version }}
         cache: 'npm'
     - run: npm ci
-    - run: npm run build --if-present
     - run: npm test
   publish:
     name: Publish
diff --git a/.gitignore b/.gitignore
index e61051f..b55927f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /node_modules/
 /coverage/
+/dist/set-cookie.cjs
\ No newline at end of file
diff --git a/.husky/pre-commit b/.husky/pre-commit
new file mode 100644
index 0000000..18de984
--- /dev/null
+++ b/.husky/pre-commit
@@ -0,0 +1 @@
+npm test
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca94cfd..6299b6d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,23 @@
 # Change log
 
+## [v3.0.0](https://github.com/nfriedly/set-cookie-parser/tree/v3.0.0) - 2025-12-17
+
+### Summary of v3 changes
+* Library now supports both ESM and CJS
+* Combined cookie headers are now split automatically
+* API has been simplified to a single named export: `parseSetCookie` (with other exports for backwards compatibility)
+
+Changed:
+* Library is now written as an ES module, with CJS automatically built for backwards-compatibility
+* `parse` function renamed to `parseSetCookie` (with alias for backwards compatibility)
+
+Added:
+* Library now splits combined cookies automatically based on input type.
+* The new `split` option overrides this behavior, set to `true` to always split or `false` for the previous behavior of never plitting automatically.
+
+Removed / Soft-deprecated:
+* default export, `parse()`, `parseString()`, and `splitCookieString()` methods are no longer documented, but are still present for backwards compatibility.
+
 ## [v2.7.2](https://github.com/nfriedly/set-cookie-parser/tree/v2.7.2) - 2025-10-27
 
 Fixed:
diff --git a/README.md b/README.md
index 4430e15..d277299 100644
--- a/README.md
+++ b/README.md
@@ -6,25 +6,11 @@
 
 ---
 
-ℹ️ **Note for current users:** I'm considering some changes for the next major version and would appreciate your feedback: https://github.com/nfriedly/set-cookie-parser/discussions/68
-
----
-
 Parses set-cookie headers into JavaScript objects
 
 Accepts a single `set-cookie` header value, an array of `set-cookie` header values, a Node.js response object, or a `fetch()` `Response` object that may have 0 or more `set-cookie` headers.
 
-Also accepts an optional options object. Defaults:
-
-```js
-{
-    decodeValues: true,  // Calls decodeURIComponent on each value - default: true
-    map: false,          // Return an object instead of an array - default: false
-    silent: false,       // Suppress the warning that is logged when called on a request instead of a response - default: false
-}
-```
-
-Returns either an array of cookie objects or a map of name => cookie object with `{map: true}`. Each cookie object will have, at a minimum `name` and `value` properties, and may have additional properties depending on the set-cookie header:
+Returns either an array of cookie objects or a map of name => cookie object with options set `{map: true}`. Each cookie object will have, at a minimum `name` and `value` properties, and may have additional properties depending on the set-cookie header:
 
 * `name` - cookie name (string)
 * `value` - cookie value (string)
@@ -36,7 +22,7 @@ Returns either an array of cookie objects or a map of name => cookie object with
 * `secure` - indicates cookie should only be sent over HTTPs (true or undefined)
 * `httpOnly` - indicates cookie should *not* be accessible to client-side JavaScript (true or undefined)
 * `sameSite` - indicates if cookie should be included in cross-site requests ([more info](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie#samesitesamesite-value)) (string or undefined)
-  * Note: valid values are `"Strict"`, `"Lax"`, and `"None"`, but set-cookie-parser coppies the value verbatim and does *not* perform any validation.
+  * Note: valid values are `"Strict"`, `"Lax"`, and `"None"`, but set-cookie-parser copies the value verbatim and does *not* perform any validation.
 * `partitioned` - indicates cookie should be scoped to the combination of 3rd party domain + top page domain ([more info](https://developer.mozilla.org/en-US/docs/Web/Privacy/Privacy_sandbox/Partitioned_cookies)) (true or undefined)
 
 (The output format is loosely based on the input format of https://www.npmjs.com/package/cookie)
@@ -53,11 +39,12 @@ $ npm install --save set-cookie-parser
 ### Get array of cookie objects
 
 ```js
-var http = require('http');
-var setCookie = require('set-cookie-parser');
+import * as http from 'node:http';
+import { parseSetCookie } from 'set-cookie-parser';
+// or const { parseSetCookie } = require('set-cookie-parser');
 
 http.get('http://example.com', function(res) {
-  var cookies = setCookie.parse(res, {
+  const cookies = parseSetCookie(res, {
     decodeValues: true  // default: true
   });
 
@@ -90,16 +77,17 @@ Example output:
 ### Get map of cookie objects
 
 ```js
-var http = require('http');
-var setCookie = require('set-cookie-parser');
+import * as http from 'node:http';
+import { parseSetCookie } from 'set-cookie-parser';
+// or const { parseSetCookie } = require('set-cookie-parser');
 
 http.get('http://example.com', function(res) {
-  var cookies = setCookie.parse(res, {
+  const cookies = parseSetCookie(res, {
     decodeValues: true,  // default: true
     map: true            // default: false
   });
 
-  var desiredCookie = cookies['session'];
+  const desiredCookie = cookies['session'];
   console.log(desiredCookie);
 });
 ```
@@ -129,12 +117,13 @@ Example output:
 This library can be used in conjunction with the [cookie](https://www.npmjs.com/package/cookie) library to modify and replace set-cookie headers:
 
 ```js
-const libCookie = require('cookie');
-const setCookie = require('set-cookie-parser');
+import * as libCookie from 'cookie';
+import { parseSetCookie } from 'set-cookie-parser';
+// or const { parseSetCookie } = require('set-cookie-parser');
 
 function modifySetCookie(res){
   // parse the set-cookie headers with this library
-  let cookies = setCookie.parse(res);
+  const cookies = parseSetCookie(res);
   
   // modify the cookies here
   // ...
@@ -148,45 +137,23 @@ function modifySetCookie(res){
 
 See a real-world example of this in [unblocker](https://github.com/nfriedly/node-unblocker/blob/08a89ec27274b46dcd80d0a324a59406f2bdad3d/lib/cookies.js#L67-L85)
 
-## Usage in React Native (and with some other fetch implementations)
-
-React Native follows the Fetch spec more closely and combines all of the Set-Cookie header values into a single string.
-The `splitCookiesString` method reverses this.
-
-```js
-var setCookie = require('set-cookie-parser');
-
-var response = fetch(/*...*/);
-
-// This is mainly for React Native; Node.js does not combine set-cookie headers.
-var combinedCookieHeader = response.headers.get('Set-Cookie');
-var splitCookieHeaders = setCookie.splitCookiesString(combinedCookieHeader)
-var cookies = setCookie.parse(splitCookieHeaders);
-
-console.log(cookies); // should be an array of cookies
-```
-
-This behavior may become a default part of parse in the next major release, but requires the extra step for now.
-
-Note that the `fetch()` spec now includes a `getSetCookie()` method that provides un-combined `Set-Cookie` headers. This library will automatically use that method if it is present.
-
 ## API
 
-### parse(input, [options])
+### parseSetCookie(input, [options])
 
 Parses cookies from a string, array of strings, or a http response object. 
 Always returns an array, regardless of input format. (Unless the `map` option is set, in which case it always returns an object.)
 
-### parseString(individualSetCookieHeader, [options])
-
-Parses a single set-cookie header value string. Options default is `{decodeValues: true}`. Used under-the-hood by `parse()`. 
-Returns an object.
-
-### splitCookiesString(combinedSetCookieHeader)
+Also accepts an optional options object. Defaults:
 
-It's uncommon, but the HTTP spec does allow for multiple of the same header to have their values combined (comma-separated) into a single header. 
-This method splits apart a combined header without choking on commas that appear within a cookie's value (or expiration date).
-Returns an array of strings that may be passed to `parse()`.
+```js
+{
+    decodeValues: true, // Calls decodeURIComponent on each value - default: true
+    map: false,         // Return an object instead of an array - default: false
+    silent: false,      // Suppress the warning that is logged when called on a request instead of a response - default: false
+    split: 'auto',      // Separate combined cookie headers. Valid options are true/false/'auto'. 'auto' splits strings but not arrays.
+}
+```
 
 ## References
 
diff --git a/build-cjs.js b/build-cjs.js
new file mode 100644
index 0000000..78e4b53
--- /dev/null
+++ b/build-cjs.js
@@ -0,0 +1,16 @@
+// Converts the ESM library file to commonJS for backwards compatibility with older node.js versions and projects
+// kind of dumb, but works better than all the "smarter" options I tried
+
+import { readFileSync, writeFileSync } from "node:fs";
+
+const inFile = "lib/set-cookie.js";
+const outFile = "dist/set-cookie.cjs";
+
+const header = `// Generated automatically from ${inFile}; see build-cjs.js\n\n`;
+const cjsExports = `module.exports = parseSetCookie;\n`; // the other exports are properties on parseSetCookie
+
+const input = readFileSync(inFile, { encoding: "utf8" });
+const output = header + input.split("// EXPORTS")[0] + cjsExports;
+writeFileSync(outFile, output);
+
+console.log(`Wrote ${output.length} bytes to ${outFile}`);
diff --git a/.eslintrc.js b/dist/.eslintrc.cjs
similarity index 82%
rename from .eslintrc.js
rename to dist/.eslintrc.cjs
index 899c92b..bf4d23b 100644
--- a/.eslintrc.js
+++ b/dist/.eslintrc.cjs
@@ -1,7 +1,7 @@
 "use strict";
 module.exports = {
   // This isn't really meant for use in browsers, but some dependents such as nookie are.
-  // So, stick with ES5 to be nice. See #44
+  // So, stick with ES5 (at least for the CJS version) to be nice. See #44
   parserOptions: { ecmaVersion: 5 },
   env: {
     node: true,
diff --git a/lib/set-cookie.js b/lib/set-cookie.js
index 2d74ca5..2c7b9b0 100644
--- a/lib/set-cookie.js
+++ b/lib/set-cookie.js
@@ -1,9 +1,8 @@
-"use strict";
-
 var defaultParseOptions = {
   decodeValues: true,
   map: false,
   silent: false,
+  split: "auto", // auto = split strings but not arrays
 };
 
 function isForbiddenKey(key) {
@@ -91,7 +90,7 @@ function parseNameValuePair(nameValuePairStr) {
   return { name: name, value: value };
 }
 
-function parse(input, options) {
+function parseSetCookie(input, options) {
   options = options
     ? Object.assign({}, defaultParseOptions, options)
     : defaultParseOptions;
@@ -129,20 +128,33 @@ function parse(input, options) {
       input = sch;
     }
   }
-  if (!Array.isArray(input)) {
+
+  var split = options.split;
+  var isArray = Array.isArray(input);
+
+  if (split === "auto") {
+    split = !isArray;
+  }
+
+  if (!isArray) {
     input = [input];
   }
 
+  input = input.filter(isNonEmptyString);
+
+  if (split) {
+    input = input.map(splitCookiesString).flat();
+  }
+
   if (!options.map) {
     return input
-      .filter(isNonEmptyString)
       .map(function (str) {
         return parseString(str, options);
       })
       .filter(Boolean);
   } else {
     var cookies = createNullObj();
-    return input.filter(isNonEmptyString).reduce(function (cookies, str) {
+    return input.reduce(function (cookies, str) {
       var cookie = parseString(str, options);
       if (cookie && !isForbiddenKey(cookie.name)) {
         cookies[cookie.name] = cookie;
@@ -236,7 +248,18 @@ function splitCookiesString(cookiesString) {
   return cookiesStrings;
 }
 
-module.exports = parse;
-module.exports.parse = parse;
-module.exports.parseString = parseString;
-module.exports.splitCookiesString = splitCookiesString;
+// named export for CJS
+parseSetCookie.parseSetCookie = parseSetCookie;
+// for backwards compatibility
+parseSetCookie.parse = parseSetCookie;
+parseSetCookie.parseString = parseString;
+parseSetCookie.splitCookiesString = splitCookiesString;
+
+// EXPORTS
+// (this section is replaced by build-cjs.js)
+
+// named export for ESM
+export { parseSetCookie };
+// for backwards compatibility
+export default parseSetCookie;
+export { parseSetCookie as parse, parseString, splitCookiesString };
diff --git a/package-lock.json b/package-lock.json
index 25e47b3..c3cc49e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
         "eslint": "^8.57.0",
         "eslint-config-prettier": "^9.1.0",
         "eslint-plugin-prettier": "^5.1.3",
-        "husky": "^9.0.11",
+        "husky": "^9.1.7",
         "mocha": "^10.3.0",
         "prettier": "^3.2.5",
         "pretty-quick": "^4.0.0",
@@ -305,9 +305,9 @@
       }
     },
     "node_modules/brace-expansion": {
-      "version": "1.1.11",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
+      "version": "1.1.12",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
+      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
       "dev": true,
       "dependencies": {
         "balanced-match": "^1.0.0",
@@ -410,9 +410,9 @@
       "dev": true
     },
     "node_modules/cross-spawn": {
-      "version": "7.0.3",
-      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
-      "integrity": "sha512-iRDPJKUPVEND7dHPO8rkbOnPpyDygcDFtWjpeWNCgy8WP2rXcxXL8TskReQl6OrB2G7+UJrags1q15Fudc7G6w==",
+      "version": "7.0.6",
+      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
+      "integrity": "sha512-uV2QOWP2nWzsy2aMp8aRibhi9dlzF5Hgh5SHaB9OiTGEyDTiJJyx0uy51QXdyWbtAHNua4XJzUKca3OzKUd3vA==",
       "dev": true,
       "dependencies": {
         "path-key": "^3.1.0",
@@ -999,12 +999,12 @@
       }
     },
     "node_modules/husky": {
-      "version": "9.0.11",
-      "resolved": "https://registry.npmjs.org/husky/-/husky-9.0.11.tgz",
-      "integrity": "sha512-AB6lFlbwwyIqMdHYhwPe+kjOC3Oc5P3nThEoW/AaO2BX3vJDjWPFxYLxokUZOo6RNX20He3AaT8sESs9NJcmEw==",
+      "version": "9.1.7",
+      "resolved": "https://registry.npmjs.org/husky/-/husky-9.1.7.tgz",
+      "integrity": "sha512-5gs5ytaNjBrh5Ow3zrvdUUY+0VxIuWVL4i9irt6friV+BqdCfmV11CQTWMiBYWHbXhco+J1kHfTOUkePhCDvMA==",
       "dev": true,
       "bin": {
-        "husky": "bin.mjs"
+        "husky": "bin.js"
       },
       "engines": {
         "node": ">=18"
@@ -1382,6 +1382,15 @@
         "node": ">= 14.0.0"
       }
     },
+    "node_modules/mocha/node_modules/brace-expansion": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.2.tgz",
+      "integrity": "sha512-Jt0vHyM+jmUBqojB7E1NIYadt0vI0Qxjxd2TErW94wDz+E2LAm5vKMXXwg6ZZBTHPuUlDgQHKXvjGBdfcF1ZDQ==",
+      "dev": true,
+      "dependencies": {
+        "balanced-match": "^1.0.0"
+      }
+    },
     "node_modules/mocha/node_modules/escape-string-regexp": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-4.0.0.tgz",
@@ -1435,15 +1444,6 @@
         "node": ">=10"
       }
     },
-    "node_modules/mocha/node_modules/minimatch/node_modules/brace-expansion": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.1.tgz",
-      "integrity": "sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==",
-      "dev": true,
-      "dependencies": {
-        "balanced-match": "^1.0.0"
-      }
-    },
     "node_modules/mocha/node_modules/supports-color": {
       "version": "8.1.1",
       "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-8.1.1.tgz",
@@ -1626,9 +1626,9 @@
       }
     },
     "node_modules/path-to-regexp": {
-      "version": "6.2.1",
-      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-6.2.1.tgz",
-      "integrity": "sha512-JLyh7xT1kizaEvcaXOQwOc2/Yhw6KZOvPf1S8401UyLk86CU79LN3vl7ztXGm/pZ+YjoyAJ4rxmHwbkBXJX+yw==",
+      "version": "6.3.0",
+      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-6.3.0.tgz",
+      "integrity": "sha512-Yhpw4T9C6hPpgPeA28us07OJeqZ5EzQTkbfwuhsUg0c237RomFoETJgmp2sa3F/41gfLE6G5cqcYwznmeEeOlQ==",
       "dev": true
     },
     "node_modules/picocolors": {
diff --git a/package.json b/package.json
index e5b6893..beb1003 100644
--- a/package.json
+++ b/package.json
@@ -9,9 +9,19 @@
     "url": "http://nfriedly.com/"
   },
   "files": [
-    "lib"
+    "lib",
+    "dist"
   ],
-  "main": "./lib/set-cookie.js",
+  "main": "./dist/set-cookie.cjs",
+  "module": "./lib/set-cookie.js",
+  "type": "module",
+  "exports": {
+    ".": {
+      "module-sync": "./lib/set-cookie.js",
+      "import": "./lib/set-cookie.js",
+      "require": "./dist/set-cookie.cjs"
+    }
+  },
   "sideEffects": false,
   "keywords": [
     "set-cookie",
@@ -26,7 +36,7 @@
     "eslint": "^8.57.0",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-prettier": "^5.1.3",
-    "husky": "^9.0.11",
+    "husky": "^9.1.7",
     "mocha": "^10.3.0",
     "prettier": "^3.2.5",
     "pretty-quick": "^4.0.0",
@@ -34,9 +44,11 @@
   },
   "scripts": {
     "lint": "eslint . --ignore-pattern '!.eslintrc.js'",
-    "test": "npm run lint && mocha",
+    "test": "npm run build && npm run lint && mocha",
     "autofix": "npm run lint -- --fix",
-    "precommit": "npm test"
+    "format": "npm run lint -- --fix",
+    "build": "node ./build-cjs.js",
+    "prepare": "husky"
   },
   "license": "MIT",
   "prettier": {
diff --git a/test/.eslintrc.js b/test/.eslintrc.cjs
similarity index 100%
rename from test/.eslintrc.js
rename to test/.eslintrc.cjs
diff --git a/test/cjs.cjs b/test/cjs.cjs
new file mode 100644
index 0000000..e15df98
--- /dev/null
+++ b/test/cjs.cjs
@@ -0,0 +1,25 @@
+const assert = require("node:assert");
+const parseSetCookie = require("../dist/set-cookie.cjs");
+
+describe("commonJS (CJS)", function () {
+
+    it('should export all methods', function() {
+        assert(typeof parseSetCookie === 'function');
+        assert(typeof parseSetCookie.parseSetCookie === 'function');
+        assert(typeof parseSetCookie.parse === 'function');
+        assert(typeof parseSetCookie.parseString === 'function');
+        assert(typeof parseSetCookie.splitCookiesString === 'function');
+    });
+
+    it('default export should work', function() {
+        var actual = parseSetCookie("foo=bar;");
+        var expected = [{ name: "foo", value: "bar" }];
+        assert.deepEqual(actual, expected);
+    });
+
+    it('named export should work', function() {
+        var actual = parseSetCookie.parse("foo=bar;");
+        var expected = [{ name: "foo", value: "bar" }];
+        assert.deepEqual(actual, expected);
+    });
+});
\ No newline at end of file
diff --git a/test/fetch.js b/test/fetch.js
index 0f610d0..43961cf 100644
--- a/test/fetch.js
+++ b/test/fetch.js
@@ -1,6 +1,5 @@
-"use strict";
-var assert = require("assert");
-var setCookie = require("../lib/set-cookie.js");
+import assert from "node:assert";
+import setCookie from "../lib/set-cookie.js";
 
 describe("fetch", () => {
   before(() => {
diff --git a/test/set-cookie-parser.js b/test/set-cookie-parser.js
index 1e1e360..980de6e 100644
--- a/test/set-cookie-parser.js
+++ b/test/set-cookie-parser.js
@@ -1,27 +1,26 @@
-"use strict";
-var assert = require("assert");
-var setCookie = require("../lib/set-cookie.js");
+import assert from "node:assert";
+import { parseSetCookie } from "../lib/set-cookie.js";
 
 describe("set-cookie-parser", function () {
   it("should parse a simple set-cookie header", function () {
-    var actual = setCookie.parse("foo=bar;");
+    var actual = parseSetCookie("foo=bar;");
     var expected = [{ name: "foo", value: "bar" }];
     assert.deepEqual(actual, expected);
   });
 
   it("should return empty array on falsy input", function () {
     var cookieStr = "";
-    var actual = setCookie.parse(cookieStr);
+    var actual = parseSetCookie(cookieStr);
     var expected = [];
     assert.deepEqual(actual, expected);
 
     cookieStr = null;
-    actual = setCookie.parse(cookieStr);
+    actual = parseSetCookie(cookieStr);
     expected = [];
     assert.deepEqual(actual, expected);
 
     cookieStr = undefined;
-    actual = setCookie.parse(cookieStr);
+    actual = parseSetCookie(cookieStr);
     expected = [];
     assert.deepEqual(actual, expected);
   });
@@ -29,7 +28,7 @@ describe("set-cookie-parser", function () {
   it("should parse a complex set-cookie header", function () {
     var cookieStr =
       "foo=bar; Max-Age=1000; Domain=.example.com; Path=/; Expires=Tue, 01 Jul 2025 10:01:11 GMT; HttpOnly; Secure; Partitioned";
-    var actual = setCookie.parse(cookieStr);
+    var actual = parseSetCookie(cookieStr);
     var expected = [
       {
         name: "foo",
@@ -49,7 +48,7 @@ describe("set-cookie-parser", function () {
   it("should parse a weird but valid cookie", function () {
     var cookieStr =
       "foo=bar=bar&foo=foo&John=Doe&Doe=John; Max-Age=1000; Domain=.example.com; Path=/; HttpOnly; Secure";
-    var actual = setCookie.parse(cookieStr);
+    var actual = parseSetCookie(cookieStr);
     var expected = [
       {
         name: "foo",
@@ -66,13 +65,13 @@ describe("set-cookie-parser", function () {
 
   it("should parse a cookie with percent-encoding in the data", function () {
     var cookieStr = "foo=asdf%3Basdf%3Dtrue%3Basdf%3Dasdf%3Basdf%3Dtrue%40asdf";
-    var actual = setCookie.parse(cookieStr);
+    var actual = parseSetCookie(cookieStr);
     var expected = [
       { name: "foo", value: "asdf;asdf=true;asdf=asdf;asdf=true@asdf" },
     ];
     assert.deepEqual(actual, expected);
 
-    actual = setCookie.parse(cookieStr, { decodeValues: false });
+    actual = parseSetCookie(cookieStr, { decodeValues: false });
     expected = [
       {
         name: "foo",
@@ -81,7 +80,7 @@ describe("set-cookie-parser", function () {
     ];
     assert.deepEqual(actual, expected);
 
-    actual = setCookie.parse(cookieStr, { decodeValues: true });
+    actual = parseSetCookie(cookieStr, { decodeValues: true });
     expected = [
       { name: "foo", value: "asdf;asdf=true;asdf=asdf;asdf=true@asdf" },
     ];
@@ -91,7 +90,7 @@ describe("set-cookie-parser", function () {
   it("should handle the case when value is not UTF-8 encoded", function () {
     var cookieStr =
       "foo=R%F3r%EB%80%8DP%FF%3B%2C%23%9A%0CU%8E%A2C8%D7%3C%3C%B0%DF%17%60%F7Y%DB%16%8BQ%D6%1A";
-    var actual = setCookie.parse(cookieStr, { decodeValues: true });
+    var actual = parseSetCookie(cookieStr, { decodeValues: true });
     var expected = [
       {
         name: "foo",
@@ -107,7 +106,7 @@ describe("set-cookie-parser", function () {
       "bam=baz",
       "foo=bar; Max-Age=1000; Domain=.example.com; Path=/; Expires=Tue, 01 Jul 2025 10:01:11 GMT; HttpOnly; Secure",
     ];
-    var actual = setCookie.parse(cookieStrs);
+    var actual = parseSetCookie(cookieStrs);
     var expected = [
       { name: "bam", value: "baz" },
       {
@@ -133,7 +132,7 @@ describe("set-cookie-parser", function () {
         ],
       },
     };
-    var actual = setCookie.parse(mockResponse);
+    var actual = parseSetCookie(mockResponse);
     var expected = [
       { name: "bam", value: "baz" },
       {
@@ -160,7 +159,7 @@ describe("set-cookie-parser", function () {
         ],
       },
     };
-    var actual = setCookie.parse(mockResponse);
+    var actual = parseSetCookie(mockResponse);
     var expected = [
       { name: "bam", value: "baz" },
       {
@@ -182,7 +181,7 @@ describe("set-cookie-parser", function () {
     var mockResponse = {
       headers: {},
     };
-    var actual = setCookie.parse(mockResponse);
+    var actual = parseSetCookie(mockResponse);
     var expected = [];
     assert.deepEqual(actual, expected);
   });
@@ -190,7 +189,7 @@ describe("set-cookie-parser", function () {
   it("should return object of cookies when result option is set to map", function () {
     var cookieStr =
       "foo=bar; Max-Age=1000; Domain=.example.com; Path=/; Expires=Tue, 01 Jul 2025 10:01:11 GMT; HttpOnly; Secure";
-    var actual = setCookie.parse(cookieStr, { map: true });
+    var actual = parseSetCookie(cookieStr, { map: true });
     var expected = {
       foo: {
         name: "foo",
@@ -208,43 +207,93 @@ describe("set-cookie-parser", function () {
 
   it("should return empty object on falsy input when result options is set to map", function () {
     var cookieStr = "";
-    var actual = setCookie.parse(cookieStr, { map: true });
+    var actual = parseSetCookie(cookieStr, { map: true });
     var expected = {};
     assert.deepEqual(actual, expected);
 
     cookieStr = null;
-    actual = setCookie.parse(cookieStr, { map: true });
+    actual = parseSetCookie(cookieStr, { map: true });
     expected = {};
     assert.deepEqual(actual, expected);
 
     cookieStr = undefined;
-    actual = setCookie.parse(cookieStr, { map: true });
+    actual = parseSetCookie(cookieStr, { map: true });
     expected = {};
     assert.deepEqual(actual, expected);
   });
 
   it("should have empty name string, and value is the name-value-pair if the name-value-pair string lacks a = character", function () {
-    var actual = setCookie.parse("foo;");
+    var actual = parseSetCookie("foo;");
     var expected = [{ name: "", value: "foo" }];
 
     assert.deepEqual(actual, expected);
 
-    actual = setCookie.parse("foo;SameSite=None;Secure");
+    actual = parseSetCookie("foo;SameSite=None;Secure");
     expected = [{ name: "", value: "foo", sameSite: "None", secure: true }];
     assert.deepEqual(actual, expected);
   });
 
   it("should skip cookies that could pollute the object prototype", function () {
-    var actual = setCookie.parse("__proto__=test;");
+    var actual = parseSetCookie("__proto__=test;");
     var expected = [];
     assert.deepEqual(actual, expected);
 
-    actual = setCookie.parse("foo;__proto__=None;Secure");
+    actual = parseSetCookie("foo;__proto__=None;Secure");
     expected = [{ name: "", value: "foo", secure: true }];
     assert.deepEqual(actual, expected);
 
-    actual = setCookie.parse("__proto__=test;", { map: true });
+    actual = parseSetCookie("__proto__=test;", { map: true });
     expected = {};
     assert.deepEqual(actual, expected);
   });
+
+  describe("split option", function () {
+    const cookieA = "a=b";
+    const cookieB = "b=c";
+    const cookieC = "c=d";
+    const combinedCookies = `${cookieA}, ${cookieB}`;
+
+    it("should split when true", function () {
+      var actual = parseSetCookie(combinedCookies, { split: true });
+      var expected = [
+        { name: "a", value: "b" },
+        { name: "b", value: "c" },
+      ];
+      assert.deepEqual(actual, expected);
+    });
+
+    it("should not split when false", function () {
+      var actual = parseSetCookie(combinedCookies, { split: false });
+      var expected = [{ name: "a", value: "b, b=c" }];
+      assert.deepEqual(actual, expected);
+    });
+
+    it("should split strings by default", function () {
+      var actual = parseSetCookie(combinedCookies);
+      var expected = [
+        { name: "a", value: "b" },
+        { name: "b", value: "c" },
+      ];
+      assert.deepEqual(actual, expected);
+    });
+
+    it("should not split arrays by default", function () {
+      var actual = parseSetCookie([combinedCookies, cookieC]);
+      var expected = [
+        { name: "a", value: "b, b=c" },
+        { name: "c", value: "d" },
+      ];
+      assert.deepEqual(actual, expected);
+    });
+
+    it("should split arrays when true", function () {
+      var actual = parseSetCookie([combinedCookies, cookieC], { split: true });
+      var expected = [
+        { name: "a", value: "b" },
+        { name: "b", value: "c" },
+        { name: "c", value: "d" },
+      ];
+      assert.deepEqual(actual, expected);
+    });
+  });
 });
diff --git a/test/split-cookies-string.js b/test/split-cookies-string.js
index 1b044d7..73032a4 100644
--- a/test/split-cookies-string.js
+++ b/test/split-cookies-string.js
@@ -1,8 +1,5 @@
-"use strict";
-var assert = require("assert");
-var setCookie = require("../lib/set-cookie.js");
-
-const splitCookiesString = setCookie.splitCookiesString;
+import assert from "node:assert";
+import { splitCookiesString } from "../lib/set-cookie.js";
 
 const array = ["a", "b"];
 
diff --git a/test/warnings.js b/test/warnings.js
index e2781d5..3c9ced0 100644
--- a/test/warnings.js
+++ b/test/warnings.js
@@ -1,8 +1,7 @@
-"use strict";
-var sinon = require("sinon");
-var setCookie = require("../lib/set-cookie.js");
+import sinon from "sinon";
+import setCookie from "../lib/set-cookie.js";
 
-describe("set-cookie-parser", function () {
+describe("warnings", function () {
   var sandbox = sinon.createSandbox();
 
   afterEach(function () {