diff --git a/workspaces/libnpmpublish/lib/get-pathname.js b/workspaces/libnpmpublish/lib/get-pathname.js
new file mode 100644
index 0000000000000..a0001465cfae6
--- /dev/null
+++ b/workspaces/libnpmpublish/lib/get-pathname.js
@@ -0,0 +1,22 @@
+'use strict'
+
+const { URL } = require('url')
+
+// given a tarball url and a registry url, returns just the
+// relevant pathname portion of it, so that it can be handled
+// elegantly by npm-registry-fetch which only expects pathnames
+// and handles the registry hostname via opts
+function getPathname (tarball, registry) {
+  const registryUrl = new URL(registry).pathname.substring(1)
+  let tarballUrl = new URL(tarball).pathname.substring(1)
+
+  // test the tarball url to see if it starts with a possible
+  // pathname from the registry url, in that case strips that portion
+  // of it so that we only return the post-registry-url pathname
+  if (registryUrl) {
+    tarballUrl = tarballUrl.substring(registryUrl.length)
+  }
+  return tarballUrl
+}
+
+module.exports = getPathname
diff --git a/workspaces/libnpmpublish/lib/unpublish.js b/workspaces/libnpmpublish/lib/unpublish.js
index 7fbeea503a337..7dc2bf0675b00 100644
--- a/workspaces/libnpmpublish/lib/unpublish.js
+++ b/workspaces/libnpmpublish/lib/unpublish.js
@@ -3,7 +3,7 @@
 const npa = require('npm-package-arg')
 const npmFetch = require('npm-registry-fetch')
 const semver = require('semver')
-const { URL } = require('url')
+const getPathname = require('./get-pathname.js')
 
 const unpublish = async (spec, opts) => {
   spec = npa(spec)
@@ -82,7 +82,7 @@ const unpublish = async (spec, opts) => {
         ...opts,
         query: { write: true },
       })
-      const tarballUrl = new URL(dist.tarball).pathname.substr(1)
+      const tarballUrl = getPathname(dist.tarball, opts.registry)
       await npmFetch(`${tarballUrl}/-rev/${_rev}`, {
         ...opts,
         method: 'DELETE',
diff --git a/workspaces/libnpmpublish/test/get-pathname.js b/workspaces/libnpmpublish/test/get-pathname.js
new file mode 100644
index 0000000000000..c2a60c7015b21
--- /dev/null
+++ b/workspaces/libnpmpublish/test/get-pathname.js
@@ -0,0 +1,20 @@
+'use strict'
+
+const t = require('tap')
+const getPathname = require('../lib/get-pathname.js')
+
+const defaultRegistry = 'https://registry.npmjs.org/'
+const pathnameRegistry =
+  'https://artifactory.example.com/api/npm/npm-snapshots/'
+
+t.equal(
+  getPathname(`${defaultRegistry}foo/bar`, defaultRegistry),
+  'foo/bar',
+  'should match a pathname in default registry'
+)
+
+t.equal(
+  getPathname(`${pathnameRegistry}foo/bar`, pathnameRegistry),
+  'foo/bar',
+  'should match a pathname in default registry'
+)
diff --git a/workspaces/libnpmpublish/test/unpublish.js b/workspaces/libnpmpublish/test/unpublish.js
index 6fbe802766024..b59dad6d36a06 100644
--- a/workspaces/libnpmpublish/test/unpublish.js
+++ b/workspaces/libnpmpublish/test/unpublish.js
@@ -134,6 +134,61 @@ t.test('unpublish specific version', async t => {
   t.ok(ret, 'foo was unpublished')
 })
 
+t.test('unpublishing from a custom registry', async t => {
+  const opt = {
+    registry: 'https://artifactory.example.com/api/npm/npm-snapshots/',
+  }
+  const reg = opt.registry
+  const doc = {
+    _id: 'foo',
+    _rev: REV,
+    _revisions: [1, 2, 3],
+    _attachments: [1, 2, 3],
+    name: 'foo',
+    'dist-tags': {
+      latest: '1.0.1',
+    },
+    versions: {
+      '1.0.0': {
+        name: 'foo',
+        dist: {
+          tarball: `${reg}/foo/-/foo-1.0.0.tgz`,
+        },
+      },
+      '1.0.1': {
+        name: 'foo',
+        dist: {
+          tarball: `${reg}/foo/-/foo-1.0.1.tgz`,
+        },
+      },
+    },
+  }
+  const postEdit = {
+    _id: 'foo',
+    _rev: REV,
+    name: 'foo',
+    'dist-tags': {
+      latest: '1.0.0',
+    },
+    versions: {
+      '1.0.0': {
+        name: 'foo',
+        dist: {
+          tarball: `${reg}/foo/-/foo-1.0.0.tgz`,
+        },
+      },
+    },
+  }
+
+  const srv = tnock(t, reg)
+  srv.get('/foo?write=true').reply(200, doc)
+  srv.put(`/foo/-rev/${REV}`, postEdit).reply(200)
+  srv.get('/foo?write=true').reply(200, postEdit)
+  srv.delete(`/foo/-/foo-1.0.1.tgz/-rev/${REV}`).reply(200)
+  const ret = await unpub('foo@1.0.1', opt)
+  t.ok(ret, 'foo was unpublished')
+})
+
 t.test('404 considered a success', async t => {
   const srv = tnock(t, REG)
   srv.get('/foo?write=true').reply(404)