diff --git a/lib/verify-auth.js b/lib/verify-auth.js
index d4605632..00f4ba44 100644
--- a/lib/verify-auth.js
+++ b/lib/verify-auth.js
@@ -5,6 +5,8 @@ const getError = require('./get-error');
 const getRegistry = require('./get-registry');
 const setNpmrcAuth = require('./set-npmrc-auth');
 
+const memo = {};
+
 module.exports = async (npmrc, pkg, context) => {
   const {
     cwd,
@@ -17,12 +19,20 @@ module.exports = async (npmrc, pkg, context) => {
   await setNpmrcAuth(npmrc, registry, context);
 
   if (normalizeUrl(registry) === normalizeUrl(DEFAULT_NPM_REGISTRY)) {
+    const key = npmrc + registry;
+    if (memo[key]) {
+      return memo[key];
+    }
+
     try {
       const whoamiResult = execa('npm', ['whoami', '--userconfig', npmrc, '--registry', registry], {cwd, env});
       whoamiResult.stdout.pipe(stdout, {end: false});
       whoamiResult.stderr.pipe(stderr, {end: false});
+
+      memo[key] = whoamiResult;
       await whoamiResult;
     } catch {
+      memo[key] = undefined;
       throw new AggregateError([getError('EINVALIDNPMTOKEN', {registry})]);
     }
   }
diff --git a/test/verify-auth.test.js b/test/verify-auth.test.js
new file mode 100644
index 00000000..ea9fd469
--- /dev/null
+++ b/test/verify-auth.test.js
@@ -0,0 +1,43 @@
+const test = require('ava');
+const {stub} = require('sinon');
+const tempy = require('tempy');
+
+const getRegistryPath = require.resolve('../lib/get-registry');
+const verifyAuthPath = require.resolve('../lib/verify-auth');
+const setNmprcAuthPath = require.resolve('../lib/set-npmrc-auth');
+const execaPath = require.resolve('execa');
+
+const resetModuleCache = () => {
+  require.cache[getRegistryPath] = undefined;
+  require.cache[verifyAuthPath] = undefined;
+  require.cache[setNmprcAuthPath] = undefined;
+  require.cache[execaPath] = undefined;
+};
+
+test.before(resetModuleCache);
+test.after(resetModuleCache);
+
+test('Verify `npm-whoami` calls memoization', async (t) => {
+  const pkg = {};
+  const context = {cwd: tempy.directory(), env: {}};
+  const fakeExeca = stub().returns({stdout: {pipe() {}}, stderr: {pipe() {}}});
+
+  require.cache[getRegistryPath] = {id: getRegistryPath, exports: () => 'https://registry.npmjs.org/'};
+  require.cache[setNmprcAuthPath] = {id: setNmprcAuthPath, exports: () => {}};
+  require.cache[execaPath] = {id: execaPath, exports: fakeExeca};
+
+  const verifyAuth = require('../lib/verify-auth');
+
+  await verifyAuth('foo', pkg, context);
+  await verifyAuth('foo', pkg, context);
+  await verifyAuth('foo', pkg, context);
+
+  t.assert(fakeExeca.calledOnce);
+
+  fakeExeca.resetHistory();
+
+  await verifyAuth('foo', pkg, context);
+  await verifyAuth('bar', pkg, context);
+
+  t.assert(fakeExeca.calledTwice);
+});