diff --git a/lib/pr_checker.js b/lib/pr_checker.js
index 8128ef0d..10968da5 100644
--- a/lib/pr_checker.js
+++ b/lib/pr_checker.js
@@ -177,11 +177,11 @@ export default class PRChecker {
       }
       const [, requester] = comment.bodyText.match(FAST_TRACK_RE);
       const collaborators = Array.from(this.data.collaborators.values(),
-        (c) => c.login);
+        (c) => c.login.toLowerCase());
       const approvals = comment.reactions.nodes.filter((r) =>
         r.user.login !== requester &&
         r.user.login !== pr.author.login &&
-        collaborators.includes(r.user.login)).length;
+        collaborators.includes(r.user.login.toLowerCase())).length;
 
       if (requester === pr.author.login && approvals < 2) {
         cli.error('The fast-track request requires' +
diff --git a/test/fixtures/comments_with_two_fast_track_different_case.json b/test/fixtures/comments_with_two_fast_track_different_case.json
new file mode 100644
index 00000000..19dc7db5
--- /dev/null
+++ b/test/fixtures/comments_with_two_fast_track_different_case.json
@@ -0,0 +1,16 @@
+[
+  {
+    "publishedAt": "2017-10-22T05:16:36.458Z",
+    "bodyText": "Fast-track has been requested by @bar. Please 👍 to approve.",
+    "author": {
+      "login": "github-actions"
+    },
+    "reactions": {
+      "nodes": [
+        { "user": { "login": "Bar" } },
+        { "user": { "login": "Foo" } },
+        { "user": { "login": "BAZ" } }
+      ]
+    }
+  }
+]
diff --git a/test/fixtures/data.js b/test/fixtures/data.js
index f53f5182..b60fe933 100644
--- a/test/fixtures/data.js
+++ b/test/fixtures/data.js
@@ -37,6 +37,8 @@ export const requestingChangesReviews =
 export const commentsWithFastTrack = readJSON('comments_with_fast_track.json');
 export const commentsWithTwoFastTrack =
   readJSON('comments_with_two_fast_track.json');
+export const commentsWithTwoFastTrackDifferentCase =
+  readJSON('comments_with_two_fast_track_different_case.json');
 export const commentsWithFastTrackInsuffientApprovals =
   readJSON('comments_with_fast_track_insufficient_approvals.json');
 export const commentsWithCI = readJSON('comments_with_ci.json');
diff --git a/test/unit/pr_checker.test.js b/test/unit/pr_checker.test.js
index 761bb83b..86ff437c 100644
--- a/test/unit/pr_checker.test.js
+++ b/test/unit/pr_checker.test.js
@@ -18,6 +18,7 @@ import {
   noReviewers,
   commentsWithFastTrack,
   commentsWithTwoFastTrack,
+  commentsWithTwoFastTrackDifferentCase,
   commentsWithFastTrackInsuffientApprovals,
   commentsWithCI,
   commentsWithFailedCI,
@@ -582,6 +583,53 @@ describe('PRChecker', () => {
       cli.assertCalledWith(expectedLogs);
     });
 
+    it('should compare collaborator handles as case-insensitive', () => {
+      const cli = new TestCLI();
+
+      const expectedLogs = {
+        ok:
+         [['Approvals: 4'],
+           ['- Foo User (@foo): https://github.com/nodejs/node/pull/16438#pullrequestreview-71480624'],
+           ['- Quux User (@Quux): LGTM'],
+           ['- Baz User (@Baz): https://github.com/nodejs/node/pull/16438#pullrequestreview-71488236'],
+           ['- Bar User (@bar) (TSC): lgtm']],
+        info:
+         [['This PR was created on Fri, 30 Nov 2018 17:50:44 GMT'],
+           ['This PR is being fast-tracked']]
+      };
+
+      const pr = Object.assign({}, firstTimerPR, {
+        author: {
+          login: 'bar'
+        },
+        createdAt: LT_48H,
+        labels: {
+          nodes: [
+            { name: 'fast-track' }
+          ]
+        }
+      });
+
+      const data = {
+        pr,
+        reviewers: allGreenReviewers,
+        comments: commentsWithTwoFastTrackDifferentCase,
+        reviews: approvingReviews,
+        commits: [],
+        collaborators,
+        authorIsNew: () => true,
+        getThread() {
+          return PRData.prototype.getThread.call(this);
+        }
+      };
+      const checker = new PRChecker(cli, data, {}, argv);
+
+      cli.clearCalls();
+      const status = checker.checkReviewsAndWait(new Date(NOW));
+      assert(status);
+      cli.assertCalledWith(expectedLogs);
+    });
+
     it('should error with 1 fast-track approval from the pr author', () => {
       const cli = new TestCLI();