diff --git src/wp-cron.php src/wp-cron.php
index 1a944c216e..d3ab354eda 100644
--- src/wp-cron.php
+++ src/wp-cron.php
@@ -20,8 +20,11 @@ ignore_user_abort( true );
 
 /* Don't make the request block till we finish, if possible. */
 if ( function_exists( 'fastcgi_finish_request' ) && version_compare( phpversion(), '7.0.16', '>=' ) ) {
-	header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );
-	header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );
+	if ( ! headers_sent() ) {
+		header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );
+		header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );
+	}
+
 	fastcgi_finish_request();
 }