diff --git a/nginx/nginx.conf b/nginx/nginx.conf
index e8fc8d74..ed5f72af 100644
--- a/nginx/nginx.conf
+++ b/nginx/nginx.conf
@@ -210,7 +210,7 @@ http {
             add_header Cache-Control "public, max-age=604800";
         }
 
-        location ~ "\.(css|js|svg)$" {
+        location ~ "\.(css|js|mjs|svg)$" {
             include /etc/nginx/snippets/security-headers.conf;
             add_header Cache-Control "public, max-age=31536000";
         }