diff --git a/dist/index.js b/dist/index.js
index ca2ed575..a67a34d4 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -2448,6 +2448,12 @@ function createMessageCard(notificationSummary, notificationColor, commit, autho
             avatar_url = author.avatar_url;
         }
     }
+    let author_url = '';
+    if (author) {
+        if (author.login && author.html_url) {
+            author_url = `[(@${author.login})](${author.html_url})`;
+        }
+    }
     const messageCard = {
         '@type': 'MessageCard',
         '@context': 'https://schema.org/extensions',
@@ -2458,7 +2464,7 @@ function createMessageCard(notificationSummary, notificationColor, commit, autho
             {
                 activityTitle: `**CI #${runNum} (commit ${sha.substr(0, 7)})** on [${repoName}](${repoUrl})`,
                 activityImage: avatar_url,
-                activitySubtitle: `by ${commit.data.commit.author.name} [(@${author.login})](${author.html_url}) on ${timestamp}`
+                activitySubtitle: `by ${commit.data.commit.author.name} ${author_url} on ${timestamp}`
             }
         ],
         potentialAction: [
@@ -5041,7 +5047,7 @@ module.exports = require("assert");
 /***/ 361:
 /***/ (function(module) {
 
-module.exports = {"_args":[["axios@0.19.2","/Users/jdcargile/projects/ms-teams-notification"]],"_from":"axios@0.19.2","_id":"axios@0.19.2","_inBundle":false,"_integrity":"sha512-fjgm5MvRHLhx+osE2xoekY70AhARk3a6hkN+3Io1jc00jtquGvxYlKlsFUhmUET0V5te6CcZI7lcv2Ym61mjHA==","_location":"/axios","_phantomChildren":{},"_requested":{"type":"version","registry":true,"raw":"axios@0.19.2","name":"axios","escapedName":"axios","rawSpec":"0.19.2","saveSpec":null,"fetchSpec":"0.19.2"},"_requiredBy":["/"],"_resolved":"https://registry.npmjs.org/axios/-/axios-0.19.2.tgz","_spec":"0.19.2","_where":"/Users/jdcargile/projects/ms-teams-notification","author":{"name":"Matt Zabriskie"},"browser":{"./lib/adapters/http.js":"./lib/adapters/xhr.js"},"bugs":{"url":"https://github.com/axios/axios/issues"},"bundlesize":[{"path":"./dist/axios.min.js","threshold":"5kB"}],"dependencies":{"follow-redirects":"1.5.10"},"description":"Promise based HTTP client for the browser and node.js","devDependencies":{"bundlesize":"^0.17.0","coveralls":"^3.0.0","es6-promise":"^4.2.4","grunt":"^1.0.2","grunt-banner":"^0.6.0","grunt-cli":"^1.2.0","grunt-contrib-clean":"^1.1.0","grunt-contrib-watch":"^1.0.0","grunt-eslint":"^20.1.0","grunt-karma":"^2.0.0","grunt-mocha-test":"^0.13.3","grunt-ts":"^6.0.0-beta.19","grunt-webpack":"^1.0.18","istanbul-instrumenter-loader":"^1.0.0","jasmine-core":"^2.4.1","karma":"^1.3.0","karma-chrome-launcher":"^2.2.0","karma-coverage":"^1.1.1","karma-firefox-launcher":"^1.1.0","karma-jasmine":"^1.1.1","karma-jasmine-ajax":"^0.1.13","karma-opera-launcher":"^1.0.0","karma-safari-launcher":"^1.0.0","karma-sauce-launcher":"^1.2.0","karma-sinon":"^1.0.5","karma-sourcemap-loader":"^0.3.7","karma-webpack":"^1.7.0","load-grunt-tasks":"^3.5.2","minimist":"^1.2.0","mocha":"^5.2.0","sinon":"^4.5.0","typescript":"^2.8.1","url-search-params":"^0.10.0","webpack":"^1.13.1","webpack-dev-server":"^1.14.1"},"homepage":"https://github.com/axios/axios","keywords":["xhr","http","ajax","promise","node"],"license":"MIT","main":"index.js","name":"axios","repository":{"type":"git","url":"git+https://github.com/axios/axios.git"},"scripts":{"build":"NODE_ENV=production grunt build","coveralls":"cat coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js","examples":"node ./examples/server.js","fix":"eslint --fix lib/**/*.js","postversion":"git push && git push --tags","preversion":"npm test","start":"node ./sandbox/server.js","test":"grunt test && bundlesize","version":"npm run build && grunt version && git add -A dist && git add CHANGELOG.md bower.json package.json"},"typings":"./index.d.ts","version":"0.19.2"};
+module.exports = {"_args":[["axios@0.19.2","/home/pcadmin/Sources/ms-teams-notification"]],"_from":"axios@0.19.2","_id":"axios@0.19.2","_inBundle":false,"_integrity":"sha512-fjgm5MvRHLhx+osE2xoekY70AhARk3a6hkN+3Io1jc00jtquGvxYlKlsFUhmUET0V5te6CcZI7lcv2Ym61mjHA==","_location":"/axios","_phantomChildren":{},"_requested":{"type":"version","registry":true,"raw":"axios@0.19.2","name":"axios","escapedName":"axios","rawSpec":"0.19.2","saveSpec":null,"fetchSpec":"0.19.2"},"_requiredBy":["/"],"_resolved":"https://registry.npmjs.org/axios/-/axios-0.19.2.tgz","_spec":"0.19.2","_where":"/home/pcadmin/Sources/ms-teams-notification","author":{"name":"Matt Zabriskie"},"browser":{"./lib/adapters/http.js":"./lib/adapters/xhr.js"},"bugs":{"url":"https://github.com/axios/axios/issues"},"bundlesize":[{"path":"./dist/axios.min.js","threshold":"5kB"}],"dependencies":{"follow-redirects":"1.5.10"},"description":"Promise based HTTP client for the browser and node.js","devDependencies":{"bundlesize":"^0.17.0","coveralls":"^3.0.0","es6-promise":"^4.2.4","grunt":"^1.0.2","grunt-banner":"^0.6.0","grunt-cli":"^1.2.0","grunt-contrib-clean":"^1.1.0","grunt-contrib-watch":"^1.0.0","grunt-eslint":"^20.1.0","grunt-karma":"^2.0.0","grunt-mocha-test":"^0.13.3","grunt-ts":"^6.0.0-beta.19","grunt-webpack":"^1.0.18","istanbul-instrumenter-loader":"^1.0.0","jasmine-core":"^2.4.1","karma":"^1.3.0","karma-chrome-launcher":"^2.2.0","karma-coverage":"^1.1.1","karma-firefox-launcher":"^1.1.0","karma-jasmine":"^1.1.1","karma-jasmine-ajax":"^0.1.13","karma-opera-launcher":"^1.0.0","karma-safari-launcher":"^1.0.0","karma-sauce-launcher":"^1.2.0","karma-sinon":"^1.0.5","karma-sourcemap-loader":"^0.3.7","karma-webpack":"^1.7.0","load-grunt-tasks":"^3.5.2","minimist":"^1.2.0","mocha":"^5.2.0","sinon":"^4.5.0","typescript":"^2.8.1","url-search-params":"^0.10.0","webpack":"^1.13.1","webpack-dev-server":"^1.14.1"},"homepage":"https://github.com/axios/axios","keywords":["xhr","http","ajax","promise","node"],"license":"MIT","main":"index.js","name":"axios","repository":{"type":"git","url":"git+https://github.com/axios/axios.git"},"scripts":{"build":"NODE_ENV=production grunt build","coveralls":"cat coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js","examples":"node ./examples/server.js","fix":"eslint --fix lib/**/*.js","postversion":"git push && git push --tags","preversion":"npm test","start":"node ./sandbox/server.js","test":"grunt test && bundlesize","version":"npm run build && grunt version && git add -A dist && git add CHANGELOG.md bower.json package.json"},"typings":"./index.d.ts","version":"0.19.2"};
 
 /***/ }),
 
diff --git a/src/message-card.ts b/src/message-card.ts
index 79d2cb68..09650517 100644
--- a/src/message-card.ts
+++ b/src/message-card.ts
@@ -17,6 +17,12 @@ export function createMessageCard(
       avatar_url = author.avatar_url
     }
   }
+  let author_url = ''
+  if (author) {
+    if (author.login && author.html_url) {
+      author_url = `[(@${author.login})](${author.html_url})`
+    }
+  }
   const messageCard = {
     '@type': 'MessageCard',
     '@context': 'https://schema.org/extensions',
@@ -30,7 +36,7 @@ export function createMessageCard(
           7
         )})** on [${repoName}](${repoUrl})`,
         activityImage: avatar_url,
-        activitySubtitle: `by ${commit.data.commit.author.name} [(@${author.login})](${author.html_url}) on ${timestamp}`
+        activitySubtitle: `by ${commit.data.commit.author.name} ${author_url} on ${timestamp}`
       }
     ],
     potentialAction: [