diff --git a/app/lib/App/SSE/EventLoop.php b/app/lib/App/SSE/EventLoop.php
index f2767f7..4c0af69 100644
--- a/app/lib/App/SSE/EventLoop.php
+++ b/app/lib/App/SSE/EventLoop.php
@@ -24,19 +24,20 @@ class EventLoop
             session_write_close();
         }
 
-        header("Cache-Control: no-store");
-        header("Content-Type: text/event-stream");
-        header('X-Accel-Buffering: no'); // for nginx buffering
+        header('Cache-Control: no-store, must-revalidate');
+        header('Content-Type: text/event-stream');
+        // explicitly disable caching so varnish and other upstreams won't cache.
+        header('Cache-Control: no-cache, must-revalidate');
+        // instruct nginx to disable fastcgi_buffering and disable gzip
+        header('X-Accel-Buffering: no');
 
         // send headers to client indicating we are now a stream
         ob_end_flush();
         flush();
 
-        $expirationTime = time() + $this->timeLimit;
-
         $lastHeartbeat = time();
 
-        while (!connection_aborted() && time() < $expirationTime)
+        while (!connection_aborted() && time() < (time() + $this->timeLimit))
         {
             set_time_limit($this->execLimit);
             try {