diff --git a/README.md b/README.md
index 18bcf88e9..a9508e70a 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,17 @@ along with the SHA-224 hash of this version for validation.
 recommended as a security practice. Permitted values for the package manager are
 `yarn`, `npm`, and `pnpm`.
 
+You can also provide a URL to a `.js` file (which will be interpreted as a
+CommonJS module) or a `.tgz` file (which will be interpreted as a package, and
+the `"bin"` field of the `package.json` will be used to determine which file to
+use in the archive).
+
+```json
+{
+  "packageManager": "yarn@https://registry.npmjs.org/@yarnpkg/cli-dist/-/cli-dist-3.2.3.tgz#sha224.16a0797d1710d1fb7ec40ab5c3801b68370a612a9b66ba117ad9924b"
+}
+```
+
 ## Known Good Releases
 
 When running Corepack within projects that don't list a supported package
diff --git a/sources/Engine.ts b/sources/Engine.ts
index baad5dac7..f477bba13 100644
--- a/sources/Engine.ts
+++ b/sources/Engine.ts
@@ -1,16 +1,16 @@
-import {UsageError}                                           from 'clipanion';
-import fs                                                     from 'fs';
-import path                                                   from 'path';
-import process                                                from 'process';
-import semver                                                 from 'semver';
+import {UsageError}                                                                                                    from 'clipanion';
+import fs                                                                                                              from 'fs';
+import path                                                                                                            from 'path';
+import process                                                                                                         from 'process';
+import semver                                                                                                          from 'semver';
 
-import defaultConfig                                          from '../config.json';
+import defaultConfig                                                                                                   from '../config.json';
 
-import * as corepackUtils                                     from './corepackUtils';
-import * as folderUtils                                       from './folderUtils';
-import * as semverUtils                                       from './semverUtils';
-import {Config, Descriptor, Locator}                          from './types';
-import {SupportedPackageManagers, SupportedPackageManagerSet} from './types';
+import * as corepackUtils                                                                                              from './corepackUtils';
+import * as folderUtils                                                                                                from './folderUtils';
+import * as semverUtils                                                                                                from './semverUtils';
+import {Config, Descriptor, Locator, SupportedPackageManagerDescriptor, SupportedPackageManagerLocator, URLDescriptor} from './types';
+import {SupportedPackageManagers, SupportedPackageManagerSet}                                                          from './types';
 
 export type PreparedPackageManagerInfo = Awaited<ReturnType<Engine[`ensurePackageManager`]>>;
 
@@ -35,6 +35,18 @@ export class Engine {
   }
 
   getPackageManagerSpecFor(locator: Locator) {
+    if (!corepackUtils.isSupportedPackageManagerLocator(locator)) {
+      return {
+        url: locator.reference,
+        bin: {},
+        registry: {
+          type: `url`,
+          url: locator.reference,
+          fields: {},
+        },
+      };
+    }
+
     const definition = this.config.definitions[locator.name];
     if (typeof definition === `undefined`)
       throw new UsageError(`This package manager (${locator.name}) isn't supported by this corepack build`);
@@ -143,6 +155,13 @@ export class Engine {
   }
 
   async resolveDescriptor(descriptor: Descriptor, {allowTags = false, useCache = true}: {allowTags?: boolean, useCache?: boolean} = {}) {
+    if (!corepackUtils.isSupportedPackageManagerDescriptor(descriptor)) {
+      return {
+        name: descriptor.name,
+        reference: new URL(descriptor.range),
+      };
+    }
+
     const definition = this.config.definitions[descriptor.name];
     if (typeof definition === `undefined`)
       throw new UsageError(`This package manager (${descriptor.name}) isn't supported by this corepack build`);
diff --git a/sources/corepackUtils.ts b/sources/corepackUtils.ts
index db7b39d22..995ec58ad 100644
--- a/sources/corepackUtils.ts
+++ b/sources/corepackUtils.ts
@@ -1,18 +1,18 @@
-import {createHash}                                            from 'crypto';
-import {once}                                                  from 'events';
-import fs                                                      from 'fs';
-import type {Dir}                                              from 'fs';
-import Module                                                  from 'module';
-import path                                                    from 'path';
-import semver                                                  from 'semver';
-
-import * as debugUtils                                         from './debugUtils';
-import * as folderUtils                                        from './folderUtils';
-import * as fsUtils                                            from './fsUtils';
-import * as httpUtils                                          from './httpUtils';
-import * as nodeUtils                                          from './nodeUtils';
-import * as npmRegistryUtils                                   from './npmRegistryUtils';
-import {RegistrySpec, Descriptor, Locator, PackageManagerSpec} from './types';
+import {createHash}                                                                                                                           from 'crypto';
+import {once}                                                                                                                                 from 'events';
+import fs                                                                                                                                     from 'fs';
+import type {Dir}                                                                                                                             from 'fs';
+import Module                                                                                                                                 from 'module';
+import path                                                                                                                                   from 'path';
+import semver                                                                                                                                 from 'semver';
+
+import * as debugUtils                                                                                                                        from './debugUtils';
+import * as folderUtils                                                                                                                       from './folderUtils';
+import * as fsUtils                                                                                                                           from './fsUtils';
+import * as httpUtils                                                                                                                         from './httpUtils';
+import * as nodeUtils                                                                                                                         from './nodeUtils';
+import * as npmRegistryUtils                                                                                                                  from './npmRegistryUtils';
+import {RegistrySpec, Descriptor, Locator, PackageManagerSpec, SupportedPackageManagerDescriptor, SupportedPackageManagerLocator, URLLocator} from './types';
 
 export function getRegistryFromPackageManagerSpec(spec: PackageManagerSpec) {
   return process.env.COREPACK_NPM_REGISTRY
@@ -102,17 +102,46 @@ export async function findInstalledVersion(installTarget: string, descriptor: De
   return bestMatch;
 }
 
+export function   isSupportedPackageManagerDescriptor(descriptor: Descriptor): descriptor is SupportedPackageManagerDescriptor {
+  return !URL.canParse(descriptor.range);
+}
+
+export function isSupportedPackageManagerLocator(locator: Locator): locator is SupportedPackageManagerLocator {
+  return typeof locator.reference === `string`;
+}
+
+function parseURLReference(locator: URLLocator) {
+  const {hash, href} = locator.reference;
+  if (hash) {
+    return {
+      version: encodeURIComponent(href.slice(0, -hash.length)),
+      build: hash.slice(1).split(`.`),
+    };
+  }
+  return {version: href, build: []};
+}
+
 export async function installVersion(installTarget: string, locator: Locator, {spec}: {spec: PackageManagerSpec}) {
   const {default: tar} = await import(`tar`);
-  const {version, build} = semver.parse(locator.reference)!;
+  const locatorIsASupportedPackageManager = isSupportedPackageManagerLocator(locator);
+  const {version, build} = locatorIsASupportedPackageManager ? semver.parse(locator.reference)! : parseURLReference(locator);
 
   const installFolder = path.join(installTarget, locator.name, version);
   const corepackFile = path.join(installFolder, `.corepack`);
 
+  let corepackContent;
+  try {
+    if (locatorIsASupportedPackageManager) {
+      corepackContent = await fs.promises.readFile(corepackFile, `utf8`);
+    }
+  } catch (err) {
+    if ((err as nodeUtils.NodeError)?.code !== `ENOENT`) {
+      throw err;
+    }
+  }
   // Older versions of Corepack didn't generate the `.corepack` file; in
   // that case we just download the package manager anew.
-  if (fs.existsSync(corepackFile)) {
-    const corepackContent = await fs.promises.readFile(corepackFile, `utf8`);
+  if (corepackContent) {
     const corepackData = JSON.parse(corepackContent);
 
     debugUtils.log(`Reusing ${locator.name}@${locator.reference}`);
@@ -123,13 +152,18 @@ export async function installVersion(installTarget: string, locator: Locator, {s
     };
   }
 
-  const defaultNpmRegistryURL = spec.url.replace(`{}`, version);
-  const url = process.env.COREPACK_NPM_REGISTRY ?
-    defaultNpmRegistryURL.replace(
-      npmRegistryUtils.DEFAULT_NPM_REGISTRY_URL,
-      () => process.env.COREPACK_NPM_REGISTRY!,
-    ) :
-    defaultNpmRegistryURL;
+  let url: string;
+  if (locatorIsASupportedPackageManager) {
+    const defaultNpmRegistryURL = spec.url.replace(`{}`, version);
+    url = process.env.COREPACK_NPM_REGISTRY ?
+      defaultNpmRegistryURL.replace(
+        npmRegistryUtils.DEFAULT_NPM_REGISTRY_URL,
+        () => process.env.COREPACK_NPM_REGISTRY!,
+      ) :
+      defaultNpmRegistryURL;
+  } else {
+    url = decodeURIComponent(version);
+  }
 
   // Creating a temporary folder inside the install folder means that we
   // are sure it'll be in the same drive as the destination, so we can
@@ -158,6 +192,14 @@ export async function installVersion(installTarget: string, locator: Locator, {s
   const hash = stream.pipe(createHash(algo));
   await once(sendTo, `finish`);
 
+  if (!locatorIsASupportedPackageManager) {
+    if (ext === `.tgz`) {
+      spec.bin = require(path.join(tmpFolder, `package.json`)).bin;
+    } else if (ext === `.js`) {
+      spec.bin = [locator.name];
+    }
+  }
+
   const actualHash = hash.digest(`hex`);
   if (build[1] && actualHash !== build[1])
     throw new Error(`Mismatch hashes. Expected ${build[1]}, got ${actualHash}`);
diff --git a/sources/specUtils.ts b/sources/specUtils.ts
index dcf51f9b3..2e13802e6 100644
--- a/sources/specUtils.ts
+++ b/sources/specUtils.ts
@@ -12,16 +12,38 @@ export function parseSpec(raw: unknown, source: string, {enforceExactVersion = t
   if (typeof raw !== `string`)
     throw new UsageError(`Invalid package manager specification in ${source}; expected a string`);
 
-  const match = raw.match(/^(?!_)([^@]+)(?:@(.+))?$/);
-  if (match === null || (enforceExactVersion && (!match[2] || !semver.valid(match[2]))))
-    throw new UsageError(`Invalid package manager specification in ${source} (${raw}); expected a semver version${enforceExactVersion ? `` : `, range, or tag`}`);
+  const atIndex = raw.indexOf(`@`);
+
+  if (atIndex === -1 || atIndex === raw.length - 1) {
+    if (enforceExactVersion)
+      throw new UsageError(`No version specified for ${raw} in "packageManager" of ${source}`);
+
+    const name = atIndex === -1 ? raw : raw.slice(0, -1);
+    if (!isSupportedPackageManager(name))
+      throw new UsageError(`Unsupported package manager specification (${name})`);
+
+    return {
+      name, range: `*`,
+    };
+  }
+
+  const name = raw.slice(0, atIndex);
+  const range = raw.slice(atIndex + 1);
+
+  const isURL = URL.canParse(range);
+  if (!isURL) {
+    if (enforceExactVersion && !semver.valid(range))
+      throw new UsageError(`Invalid package manager specification in ${source} (${raw}); expected a semver version${enforceExactVersion ? `` : `, range, or tag`}`);
+
+    if (!isSupportedPackageManager(name)) {
+      throw new UsageError(`Unsupported package manager specification (${raw})`);
+    }
+  }
 
-  if (!isSupportedPackageManager(match[1]))
-    throw new UsageError(`Unsupported package manager specification (${match})`);
 
   return {
-    name: match[1],
-    range: match[2] ?? `*`,
+    name,
+    range,
   };
 }
 
diff --git a/sources/types.ts b/sources/types.ts
index abf4cdb8b..994e654b9 100644
--- a/sources/types.ts
+++ b/sources/types.ts
@@ -96,7 +96,8 @@ export interface Config {
  * A structure containing the information needed to locate the package
  * manager to use for the active project.
  */
-export interface Descriptor {
+export type Descriptor = SupportedPackageManagerDescriptor | URLDescriptor;
+export interface SupportedPackageManagerDescriptor {
   /**
      * The name of the package manager required.
      */
@@ -107,11 +108,24 @@ export interface Descriptor {
      */
   range: string;
 }
+interface URLDescriptor {
+  /**
+     * The name of the package manager required.
+     */
+  name: string;
+
+  /**
+     * The range of versions allowed.
+     */
+  range: string;
+}
 
 /**
  *
  */
-export interface Locator {
+export type Locator = SupportedPackageManagerLocator | URLLocator;
+
+export interface SupportedPackageManagerLocator {
   /**
      * The name of the package manager required.
      */
@@ -122,3 +136,7 @@ export interface Locator {
      */
   reference: string;
 }
+export interface URLLocator {
+  name: string;
+  reference: URL;
+}
diff --git a/tests/main.test.ts b/tests/main.test.ts
index 83bacb94c..3e4f8de07 100644
--- a/tests/main.test.ts
+++ b/tests/main.test.ts
@@ -63,10 +63,12 @@ it(`should require a version to be specified`, async () => {
   });
 });
 
-const testedPackageManagers: Array<[string, string]> = [
+const testedPackageManagers: Array<[string, string] | [string, string, string]> = [
   [`yarn`, `1.22.4`],
   [`yarn`, `1.22.4+sha1.01c1197ca5b27f21edc8bc472cd4c8ce0e5a470e`],
   [`yarn`, `1.22.4+sha224.0d6eecaf4d82ec12566fdd97143794d0f0c317e0d652bd4d1b305430`],
+  [`yarn`, `https://registry.npmjs.com/yarn/-/yarn-1.22.21.tgz`, `1.22.21`],
+  [`yarn`, `https://registry.npmjs.com/yarn/-/yarn-1.22.21.tgz#sha1.1959a18351b811cdeedbd484a8f86c3cc3bbaf72`, `1.22.21`],
   [`yarn`, `2.0.0-rc.30`],
   [`yarn`, `2.0.0-rc.30+sha1.4f0423b01bcb57f8e390b4e0f1990831f92dd1da`],
   [`yarn`, `2.0.0-rc.30+sha224.0e7a64468c358596db21c401ffeb11b6534fce7367afd3ae640eadf1`],
@@ -84,9 +86,15 @@ const testedPackageManagers: Array<[string, string]> = [
   [`npm`, `6.14.2+sha224.50512c1eb404900ee78586faa6d756b8d867ff46a328e6fb4cdf3a87`],
 ];
 
-for (const [name, version] of testedPackageManagers) {
+for (const [name, version, expectedVersion = version.split(`+`, 1)[0]] of testedPackageManagers) {
   it(`should use the right package manager version for a given project (${name}@${version})`, async () => {
     await xfs.mktempPromise(async cwd => {
+      await expect(runCli(cwd, [`${name}@${version}`, `--version`])).resolves.toMatchObject({
+        exitCode: 0,
+        stderr: ``,
+        stdout: `${expectedVersion}\n`,
+      });
+
       await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
         packageManager: `${name}@${version}`,
       });
@@ -94,7 +102,7 @@ for (const [name, version] of testedPackageManagers) {
       await expect(runCli(cwd, [name, `--version`])).resolves.toMatchObject({
         exitCode: 0,
         stderr: ``,
-        stdout: `${version.split(`+`, 1)[0]}\n`,
+        stdout: `${expectedVersion}\n`,
       });
     });
   });