diff --git a/terraform/functions/directory-index.js b/terraform/functions/directory-index.js
index 40c5758..c2e3d4f 100644
--- a/terraform/functions/directory-index.js
+++ b/terraform/functions/directory-index.js
@@ -18,7 +18,8 @@ function handler(event) {
   var request = event.request;
   var uri = request.uri;
 
-  if (RETIRED_JOB_URIS[uri]) {
+  // CloudFront does not normalize URI case. The S3 keys are lowercase.
+  if (RETIRED_JOB_URIS[uri.toLowerCase()]) {
     return {
       statusCode: 301,
       statusDescription: "Moved Permanently",