diff --git a/lib/fetcher.js b/lib/fetcher.js
index 65e97e20..d88724c5 100644
--- a/lib/fetcher.js
+++ b/lib/fetcher.js
@@ -105,8 +105,15 @@ class FetcherBase {
       this[_readPackageJson] = readPackageJsonFast
     }
 
-    // config values: npmjs (default), never
-    this.replaceRegistryHost = opts.replaceRegistryHost === 'never' ? 'never' : 'npmjs'
+    // config values: npmjs (default), never, always
+    // we don't want to mutate the original value
+    if (opts.replaceRegistryHost !== 'never'
+      && opts.replaceRegistryHost !== 'always'
+    ) {
+      this.replaceRegistryHost = 'npmjs'
+    } else {
+      this.replaceRegistryHost = opts.replaceRegistryHost
+    }
 
     this.defaultTag = opts.defaultTag || 'latest'
     this.registry = removeTrailingSlashes(opts.registry || 'https://registry.npmjs.org')
diff --git a/lib/remote.js b/lib/remote.js
index 3404ea94..14e68780 100644
--- a/lib/remote.js
+++ b/lib/remote.js
@@ -5,7 +5,7 @@ const pacoteVersion = require('../package.json').version
 const fetch = require('npm-registry-fetch')
 const Minipass = require('minipass')
 // The default registry URL is a string of great magic.
-const magic = /^https?:\/\/registry\.npmjs\.org\//
+const magicHost = 'https://registry.npmjs.org'
 
 const _cacheFetches = Symbol.for('pacote.Fetcher._cacheFetches')
 const _headers = Symbol('_headers')
@@ -13,10 +13,13 @@ class RemoteFetcher extends Fetcher {
   constructor (spec, opts) {
     super(spec, opts)
     this.resolved = this.spec.fetchSpec
-    if (this.replaceRegistryHost === 'npmjs'
-      && magic.test(this.resolved)
-      && !magic.test(this.registry + '/')) {
-      this.resolved = this.resolved.replace(magic, this.registry + '/')
+    const resolvedURL = new URL(this.resolved)
+    if (
+      (this.replaceRegistryHost === 'npmjs'
+        && resolvedURL.origin === magicHost)
+      || this.replaceRegistryHost === 'always'
+    ) {
+      this.resolved = new URL(resolvedURL.pathname, this.registry).href
     }
 
     // nam is a fermented pork sausage that is good to eat
diff --git a/test/fetcher.js b/test/fetcher.js
index 34000ab8..70811cc8 100644
--- a/test/fetcher.js
+++ b/test/fetcher.js
@@ -531,3 +531,10 @@ t.test('replace opts never', t => {
   t.equal(f.replaceRegistryHost, 'never')
   t.end()
 })
+t.test('replace opts always', t => {
+  const f = new FileFetcher('pkg.tgz', {
+    replaceRegistryHost: 'always',
+  })
+  t.equal(f.replaceRegistryHost, 'always')
+  t.end()
+})
diff --git a/test/remote.js b/test/remote.js
index 850de2eb..a39141de 100644
--- a/test/remote.js
+++ b/test/remote.js
@@ -141,3 +141,49 @@ t.test('get a timeout error from the http fetch', t => {
     code: /FETCH_ERROR|ERR_SOCKET_TIMEOUT/,
   })
 })
+
+t.test('option replaceRegistryHost', rhTest => {
+  const tnock = require('./fixtures/tnock')
+  const { join } = require('path')
+  const abbrevTGZ = fs.readFileSync(abbrev)
+
+  rhTest.test('host should be replaced if set to always on npmjs registry', async ct => {
+    const testdir = t.testdir()
+    tnock(ct, 'https://registry.github.com')
+      .get('/abbrev/-/abbrev-1.1.1.tgz')
+      .reply(200, abbrevTGZ)
+
+    const fetcher = new RemoteFetcher(
+      'https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz',
+      {
+        registry: 'https://registry.github.com',
+        cache: join(testdir, 'cache'),
+        fullReadJson: true,
+        replaceRegistryHost: 'always',
+      })
+    ct.equal(fetcher.replaceRegistryHost, 'always')
+    const tarball = await fetcher.tarball()
+    ct.match(tarball, abbrevTGZ)
+  })
+
+  rhTest.test('host should be replaced if set to always on other registry', async ct => {
+    const testdir = t.testdir()
+    tnock(ct, 'https://registry.github.com')
+      .get('/abbrev/-/abbrev-1.1.1.tgz')
+      .reply(200, abbrevTGZ)
+
+    const fetcher = new RemoteFetcher(
+      'https://registry.somethingelse.org/abbrev/-/abbrev-1.1.1.tgz',
+      {
+        registry: 'https://registry.github.com',
+        cache: join(testdir, 'cache'),
+        fullReadJson: true,
+        replaceRegistryHost: 'always',
+      })
+    ct.equal(fetcher.replaceRegistryHost, 'always')
+    const tarball = await fetcher.tarball()
+    ct.match(tarball, abbrevTGZ)
+  })
+
+  rhTest.end()
+})