diff --git a/package.json b/package.json
index dac6096..dbfe35b 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,8 @@
   "dependencies": {
     "babel-runtime": "^6.11.6",
     "isomorphic-fetch": "^2.2.1",
-    "loglevel": "^1.4.1"
+    "loglevel": "^1.4.1",
+    "url-parse": "^1.1.3"
   },
   "devDependencies": {
     "babel-cli": "^6.10.1",
diff --git a/src/util/abstract_service.js b/src/util/abstract_service.js
index 8a8e425..aba087f 100644
--- a/src/util/abstract_service.js
+++ b/src/util/abstract_service.js
@@ -15,6 +15,7 @@
  */
 
 import Http from './http';
+import URL from 'url-parse';
 
 export default class AbstractService {
 
@@ -57,10 +58,26 @@ export default class AbstractService {
    * @returns {Promise.<T>} A promise that will resolve with the list of API versions.
    */
   versions () {
-    return this.http
-      .httpGet(this._endpointUrl)
-      .then((response) => response.json())
-      .then((body) => body.versions);
+    return new Promise((resolve, reject) => {
+      let promise = this.http
+        .httpGet(this._endpointUrl)
+        .catch((response) => {
+          if (response.status === 401) {
+            let rootUrl = new URL(this._endpointUrl);
+            rootUrl.set('pathname', '/');
+            rootUrl.set('query', '');
+            rootUrl.set('hash', '');
+
+            return this.http.httpGet(rootUrl.href);
+          } else {
+            return reject(response);
+          }
+        });
+
+      promise
+        .then((response) => response.json())
+        .then((body) => resolve(body.versions));
+    });
   }
 
   /**
diff --git a/test/unit/helpers/data/versions.js b/test/unit/helpers/data/versions.js
index 47e8d97..4e160cf 100644
--- a/test/unit/helpers/data/versions.js
+++ b/test/unit/helpers/data/versions.js
@@ -23,6 +23,7 @@
  * URLs to match the test data below.
  */
 const rootUrl = "http://example.com/";
+const subUrl = `${rootUrl}/v1`;
 
 /**
  * A mock list of supported versions for the below requests.
@@ -36,7 +37,7 @@ const versions = [
 /**
  * Build a new FetchMock configuration for the versions (root) endpoint.
  *
- * @returns {{}} A full FetchMock configuration for Glance's Root Resource.
+ * @returns {{}} A full FetchMock configuration for a versions resource.
  */
 function rootResponse() {
   return {
@@ -109,8 +110,26 @@ function rootResponse() {
   };
 }
 
+/**
+ * FetchMock configuration for a 401 response against the versioned API url.
+ *
+ * @param {int} httpStatus The HTTP status for the response.
+ * @returns {{}} A full FetchMock configuration a failing request..
+ */
+function subResponse(httpStatus = 401) {
+  return {
+    method: 'GET',
+    matcher: subUrl,
+    response: {
+      status: httpStatus
+    }
+  };
+}
+
 export {
   rootUrl,
+  subUrl,
   versions,
-  rootResponse
+  rootResponse,
+  subResponse
 };
diff --git a/test/unit/util/abstract_serviceTest.js b/test/unit/util/abstract_serviceTest.js
index 7c274a8..8dd88b1 100644
--- a/test/unit/util/abstract_serviceTest.js
+++ b/test/unit/util/abstract_serviceTest.js
@@ -73,6 +73,36 @@ describe('AbstractService', () => {
         .catch((error) => done.fail(error));
     });
 
+    // This test catches the case when the service catalog already points
+    // at an API version.
+    it("Should retry at the root URL if a 401 is encountered", (done) => {
+      const service = new AbstractService(mockData.subUrl, mockData.versions);
+
+      fetchMock.mock(mockData.subResponse());
+      fetchMock.mock(mockData.rootResponse());
+
+      service.versions()
+        .then((versions) => {
+          // Quick sanity check.
+          expect(versions.length).toBe(6);
+          done();
+        })
+        .catch((error) => done.fail(error));
+    });
+
+    it("Should not retry at the root URL if a different status is encountered", (done) => {
+      const service = new AbstractService(mockData.subUrl, mockData.versions);
+
+      fetchMock.mock(mockData.subResponse(500));
+
+      service.versions()
+        .then((response) => done.fail(response))
+        .catch((error) => {
+          expect(error).not.toBeNull();
+          done();
+        });
+    });
+
     it("Should NOT cache its results", (done) => {
       const service = new AbstractService(mockData.rootUrl, mockData.versions);
       const mockOptions = mockData.rootResponse();