diff --git a/lib/release-ops.js b/lib/release-ops.js
index 4e1c6e7..3c1acfa 100644
--- a/lib/release-ops.js
+++ b/lib/release-ops.js
@@ -5,17 +5,12 @@
  * MIT License
  */
 
-/* global test, cat, rm, mv */
-
 "use strict";
 
 //------------------------------------------------------------------------------
 // Requirements
 //------------------------------------------------------------------------------
 
-// TODO: Update to use non-global module to avoid prototype pollution.
-require("shelljs/global");
-
 const fs = require("fs"),
     path = require("path"),
     semver = require("semver"),
@@ -49,6 +44,21 @@ const commitTagMap = new Map([
 //     /MIT/, /BSD/, /Apache/, /ISC/, /WTF/, /Public Domain/
 // ];
 
+/**
+ * Tests if a file exists.
+ * @param {string} file The path of the file to be tested.
+ * @returns {boolean} `true` if the specified path denotes an existing file, otherwise `false`.
+ */
+function fileExists(file) {
+
+    // We can't use the `throwIfNoEntry` option with `fs.statSync`, because it's not supported in Node.js 10,
+    // so we check if the file exists in advance.
+    if (!fs.existsSync(file)) {
+        return false;
+    }
+    return fs.statSync(file).isFile();
+}
+
 /**
  * Loads the package.json file from the current directory.
  * @returns {void}
@@ -66,7 +76,7 @@ function getPackageInfo() {
  * @private
  */
 function validateSetup() {
-    if (!test("-f", "package.json")) {
+    if (!fileExists("package.json")) {
         console.error("Missing package.json file");
         ShellOps.exit(1);
     }
@@ -333,27 +343,27 @@ function calculateReleaseInfo(prereleaseId) {
  */
 function writeChangelog(releaseInfo) {
 
-    // get most recent two tags
+    // get today's date in "mmmm d, yyyy" format
     const now = new Date(),
-        timestamp = dateformat(now, "mmmm d, yyyy");
-
-    // output header
-    (`v${releaseInfo.version} - ${timestamp}\n`).to("CHANGELOG.tmp");
+        today = dateformat(now, "mmmm d, yyyy");
 
-    // output changelog
-    (`\n${releaseInfo.rawChangelog}\n\n`).toEnd("CHANGELOG.tmp");
+    // output header and changelog
+    fs.writeFileSync(
+        "CHANGELOG.tmp",
+        `v${releaseInfo.version} - ${today}\n\n${releaseInfo.rawChangelog}\n\n`
+    );
 
     // ensure there's a CHANGELOG.md file
-    if (!test("-f", "CHANGELOG.md")) {
+    if (!fileExists("CHANGELOG.md")) {
         fs.writeFileSync("CHANGELOG.md", "");
     }
 
-    // switch-o change-o
-    // `cat` returns a ShellString and `fs.writeFileSync` is throwing an error saying that this must be a String.
-    fs.writeFileSync("CHANGELOG.md.tmp", cat("CHANGELOG.tmp", "CHANGELOG.md").toString());
-    rm("CHANGELOG.tmp");
-    rm("CHANGELOG.md");
-    mv("CHANGELOG.md.tmp", "CHANGELOG.md");
+    const data = `${fs.readFileSync("CHANGELOG.tmp", "utf-8")}${fs.readFileSync("CHANGELOG.md", "utf-8")}`;
+
+    fs.writeFileSync("CHANGELOG.md.tmp", data);
+    fs.unlinkSync("CHANGELOG.tmp");
+    fs.unlinkSync("CHANGELOG.md");
+    fs.renameSync("CHANGELOG.md.tmp", "CHANGELOG.md");
 }
 
 /**
diff --git a/package.json b/package.json
index 3486d5d..d323a8b 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,6 @@
     "dateformat": "^3.0.3",
     "github-api": "^3.2.2",
     "linefix": "^0.1.1",
-    "semver": "^6.1.1",
-    "shelljs": "^0.8.3"
+    "semver": "^6.1.1"
   }
 }
diff --git a/tests/lib/release-ops.js b/tests/lib/release-ops.js
index 9d32e15..197b947 100644
--- a/tests/lib/release-ops.js
+++ b/tests/lib/release-ops.js
@@ -12,7 +12,11 @@
 //------------------------------------------------------------------------------
 
 const assert = require("chai").assert,
+    fs = require("fs"),
     leche = require("leche"),
+    os = require("os"),
+    path = require("path"),
+    sinon = require("sinon"),
     ReleaseOps = require("../../lib/release-ops");
 
 //------------------------------------------------------------------------------
@@ -479,4 +483,65 @@ describe("ReleaseOps", () => {
         });
     });
 
+    describe("writeChangelog", () => {
+
+        const cwd = process.cwd();
+        let sandbox = null;
+        let tmpDir = null;
+
+        beforeEach(() => {
+            sandbox = sinon.sandbox.create();
+            tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "writeChangelog-"));
+            process.chdir(tmpDir);
+        });
+
+        afterEach(() => {
+            sandbox.restore();
+            sandbox = null;
+            process.chdir(cwd);
+            fs.readdirSync(tmpDir).forEach(filename => fs.unlinkSync(path.join(tmpDir, filename))); // delete files in tmpDir
+            fs.rmdirSync(tmpDir);
+            tmpDir = null;
+        });
+
+        it("creates a changelog", () => {
+            const rawChangelog =
+            "* [`bfb7759`](https://github.com/eslint/eeslint-release/commit/bfb7759a67daeb65410490b4d98bb9da7d1ea2ce) feat: First alpha (Firstname Lastname)";
+            const releaseInfo = { version: "1.0.0-alpha.0", rawChangelog };
+            const date = new Date(2024, 1, 15);
+
+            sandbox.stub(global, "Date").returns(date);
+
+            ReleaseOps.writeChangelog(releaseInfo);
+
+            assert.deepStrictEqual(fs.readdirSync("."), ["CHANGELOG.md"]);
+            const newChangelog = fs.readFileSync("CHANGELOG.md", "utf-8");
+
+            assert.strictEqual(newChangelog, `v1.0.0-alpha.0 - February 15, 2024\n\n${rawChangelog}\n\n`);
+        });
+
+        it("extends a changelog", () => {
+            const oldChangelog =
+            "v9.0.0 - December 31, 2023\n" +
+            "\n" +
+            "* [`0beec7b`](https://github.com/eslint/eeslint-release/commit/0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33) chore: Remove a dependency (𐌕𐌄𐌔𐌕)\n" +
+            "\n";
+            const rawChangelog =
+            "* [`62cdb70`](https://github.com/eslint/eeslint-release/commit/62cdb7020ff920e5aa642c3d4066950dd1f01f4d) fix: Fix something (Abc D. Efg)\n" +
+            "* [`bbe960a`](https://github.com/eslint/eeslint-release/commit/bbe960a25ea311d21d40669e93df2003ba9b90a2) test: Make sure it's broken (Francesco Trotta)";
+            const releaseInfo = { version: "10.0.0", rawChangelog };
+            const date = new Date(2024, 1, 2);
+
+            sandbox.stub(global, "Date").returns(date);
+            fs.writeFileSync("CHANGELOG.md", oldChangelog);
+
+            ReleaseOps.writeChangelog(releaseInfo);
+
+            assert.deepStrictEqual(fs.readdirSync("."), ["CHANGELOG.md"]);
+            const newChangelog = fs.readFileSync("CHANGELOG.md", "utf-8");
+
+            assert.strictEqual(newChangelog, `v10.0.0 - February 2, 2024\n\n${rawChangelog}\n\n${oldChangelog}`);
+        });
+    });
+
 });