diff --git a/README.md b/README.md
index 30dd458..cf0dab8 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,20 @@ You need to have Deno 1.46.0+ installed (latest version is recommended; just run
 deno install -gArf jsr:@deno/deployctl
 ```
 
+## Upgrade
+
+If you have `deployctl` already installed, you can upgrade to the latest version
+by running:
+
+```shell
+deployctl upgrade
+```
+
+> [!WARNING]
+> If your `deployctl` is older than 1.13.0 and you are using Deno v2.x,
+> `deployctl upgrade` does not work. You instead need to run
+> `deno install -gArf jsr:@deno/deployctl` in this case.
+
 ## Usage
 
 The easiest way to get started with `deployctl` is to deploy one of the examples
diff --git a/src/args.ts b/src/args.ts
index 90b40a0..08492a6 100644
--- a/src/args.ts
+++ b/src/args.ts
@@ -47,6 +47,7 @@ export function parseArgs(args: string[]) {
       "db",
       "env",
       "env-file",
+      "root",
     ],
     collect: [
       "grep",
diff --git a/src/subcommands/upgrade.ts b/src/subcommands/upgrade.ts
index 81788c2..ce8a5bc 100644
--- a/src/subcommands/upgrade.ts
+++ b/src/subcommands/upgrade.ts
@@ -7,6 +7,7 @@ import {
   parse as semverParse,
 } from "@std/semver";
 import { VERSION } from "../version.ts";
+import type { Args as RawArgs } from "../args.ts";
 
 const help = `deployctl upgrade
 Upgrade deployctl to the given version (defaults to latest).
@@ -29,24 +30,33 @@ ARGS:
     <version>         The version to upgrade to (defaults to latest)
 `;
 
-export interface Args {
+type UpgradeArgs = {
   help: boolean;
-}
+  /**
+   * If present, this value will be provided to `deno install` command that the
+   * upgrade subcommand internally invokes. This option is not documented in the
+   * help message as its intended use is for testing.
+   */
+  root: string | null;
+};
 
-// deno-lint-ignore no-explicit-any
-export default async function (rawArgs: Record<string, any>): Promise<void> {
-  const args: Args = {
+export default async function (rawArgs: RawArgs): Promise<void> {
+  const version = typeof rawArgs._[0] === "string" ? rawArgs._[0] : null;
+  const args: UpgradeArgs = {
     help: !!rawArgs.help,
+    root: rawArgs.root ?? null,
   };
-  const version = typeof rawArgs._[0] === "string" ? rawArgs._[0] : null;
+
   if (args.help) {
     console.log(help);
-    Deno.exit();
+    Deno.exit(0);
   }
+
   if (rawArgs._.length > 1) {
     console.error(help);
     error("Too many positional arguments given.");
   }
+
   if (version && !semverValid(version)) {
     error(`The provided version is invalid.`);
   }
@@ -70,17 +80,14 @@ export default async function (rawArgs: Record<string, any>): Promise<void> {
     const process = new Deno.Command(Deno.execPath(), {
       args: [
         "install",
-        "--allow-read",
-        "--allow-write",
-        "--allow-env",
-        "--allow-net",
-        "--allow-run",
-        "--allow-sys",
-        "--no-check",
+        "-A",
+        "--global",
+        args.root ? `--root=${args.root}` : undefined,
+        "--reload",
         "--force",
         "--quiet",
-        `https://deno.land/x/deploy@${version ? version : latest}/deployctl.ts`,
-      ],
+        `jsr:@deno/deployctl@${version || latest}`,
+      ].filter((x) => x !== undefined),
     }).spawn();
     await process.status;
   }
diff --git a/tests/upgrade_test.ts b/tests/upgrade_test.ts
new file mode 100644
index 0000000..7b688c4
--- /dev/null
+++ b/tests/upgrade_test.ts
@@ -0,0 +1,83 @@
+import { assert } from "@std/assert/assert";
+import { assertEquals } from "@std/assert/assert_equals";
+import { join } from "@std/path/join";
+import { VERSION } from "../src/version.ts";
+
+// Install the current script, then upgrade it to 1.12.0 (effectively downgrade)
+// to see if the upgrade command works as expected.
+Deno.test("upgrade", async () => {
+  const decoder = new TextDecoder();
+
+  const tempDir = await Deno.makeTempDir();
+  console.log(tempDir);
+
+  const exe = Deno.build.os === "windows" ? "deployctl.cmd" : "deployctl";
+
+  // Install the current `deployctl.ts`
+  {
+    const installCmd = await new Deno.Command(Deno.execPath(), {
+      args: [
+        "install",
+        "-A",
+        "--reload",
+        "--force",
+        "--global",
+        "--config",
+        join(Deno.cwd(), "deno.jsonc"),
+        "--root",
+        tempDir,
+        join(Deno.cwd(), "deployctl.ts"),
+      ],
+      stdout: "inherit",
+      stderr: "inherit",
+    }).output();
+    assert(installCmd.success);
+  }
+
+  // Check the version of the installed `deployctl`
+  {
+    const versionCmd = await new Deno.Command(`${tempDir}/bin/${exe}`, {
+      args: ["--version"],
+    }).output();
+    const stdout = decoder.decode(versionCmd.stdout).trim();
+    const stderr = decoder.decode(versionCmd.stderr).trim();
+    assert(versionCmd.success, `stdout: ${stdout}\nstderr: ${stderr}`);
+    assertEquals(
+      stdout,
+      `deployctl ${VERSION}`,
+      `stdout: ${stdout}\nstderr: ${stderr}`,
+    );
+  }
+
+  const UPGRADE_VERSION = "1.12.0";
+
+  // "Upgrade" the installed `deployctl` to 1.12.0
+  {
+    const upgradeCmd = await new Deno.Command(`${tempDir}/bin/${exe}`, {
+      args: [
+        "upgrade",
+        "--root",
+        tempDir,
+        UPGRADE_VERSION,
+      ],
+      stdout: "inherit",
+      stderr: "inherit",
+    }).output();
+    assert(upgradeCmd.success);
+  }
+
+  // Check the version of the "upgraded" `deployctl`
+  {
+    const versionCmd = await new Deno.Command(`${tempDir}/bin/${exe}`, {
+      args: ["--version"],
+    }).output();
+    const stdout = decoder.decode(versionCmd.stdout).trim();
+    const stderr = decoder.decode(versionCmd.stderr).trim();
+    assert(versionCmd.success);
+    assertEquals(
+      stdout,
+      `deployctl ${UPGRADE_VERSION}`,
+      `stdout: ${stdout}\nstderr: ${stderr}`,
+    );
+  }
+});