diff --git a/fetch/api/cors/cors-no-preflight.any.js b/fetch/api/cors/cors-no-preflight.any.js
index 7a0269aae4ec3dd..e3063e75a18ad79 100644
--- a/fetch/api/cors/cors-no-preflight.any.js
+++ b/fetch/api/cors/cors-no-preflight.any.js
@@ -39,3 +39,5 @@ corsNoPreflight("Cross domain [GET] [Content-Type: multipart/form-data]", host_i
 corsNoPreflight("Cross domain [GET] [Content-Type: text/plain]", host_info.HTTP_REMOTE_ORIGIN, "GET" , "Content-Type", "text/plain");
 corsNoPreflight("Cross domain [GET] [Content-Type: text/plain;charset=utf-8]", host_info.HTTP_REMOTE_ORIGIN, "GET" , "Content-Type", "text/plain;charset=utf-8");
 corsNoPreflight("Cross domain [GET] [Content-Type: Text/Plain;charset=utf-8]", host_info.HTTP_REMOTE_ORIGIN, "GET" , "Content-Type", "Text/Plain;charset=utf-8");
+corsNoPreflight("Cross domain [GET] [Last-Event-ID: evt-14]", host_info.HTTP_REMOTE_ORIGIN, "GET", "Last-Event-ID", "evt-14");
+corsNoPreflight("Cross domain [GET] [Last-Event-ID: EvT-15]", host_info.HTTP_REMOTE_ORIGIN, "GET", "Last-Event-ID", "EvT-15");
diff --git a/fetch/api/cors/resources/not-cors-safelisted.json b/fetch/api/cors/resources/not-cors-safelisted.json
index 945dc0f93ba4a30..a8a640bc66f09c5 100644
--- a/fetch/api/cors/resources/not-cors-safelisted.json
+++ b/fetch/api/cors/resources/not-cors-safelisted.json
@@ -8,6 +8,8 @@
   ["content-language", "@"],
   ["content-type", "text/html"],
   ["content-type", "text/plain; long=0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901"],
+  ["last-event-id", "\""],
+  ["lsat-event-id", "012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678"],
   ["range", "bytes 0-"],
   ["test", "hi"]
 ]