diff --git a/lib/getPackageDetails.js b/lib/getPackageDetails.js
index 728ae34..c4a98e7 100644
--- a/lib/getPackageDetails.js
+++ b/lib/getPackageDetails.js
@@ -181,7 +181,22 @@ module.exports = function getPackageDetails(
     readline.cursorTo(process.stdout, 0);
     readline.clearLine(process.stdout, 1);
     process.stdout.write(`GET ${infoUrl}`);
-    packageDetailsCache[key] = fetch(infoUrl).then(checkResponse).then((packageInfo) => {
+    const options = {
+      method: 'GET'
+    };
+
+    if (
+      process.env.PRIVATE_REGISTRY_USER &&
+      process.env.PRIVATE_REGISTRY_PASSWORD
+    ) {
+      const encoded = Buffer.from(
+        `${process.env.PRIVATE_REGISTRY_USER}:${process.env.PRIVATE_REGISTRY_PASSWORD}`
+      ).toString('base64');
+      options.headers = {
+        Authorization: `Basic ${encoded}`
+      };
+    }
+    packageDetailsCache[key] = fetch(infoUrl, options).then(checkResponse).then((packageInfo) => {
       let version;
       if (!versionLoose) {
         version = packageInfo[`dist-tags`].latest;