diff --git a/deployment/scripts/nginx/nginx.conf b/deployment/scripts/nginx/nginx.conf
index de70379..7593ca5 100644
--- a/deployment/scripts/nginx/nginx.conf
+++ b/deployment/scripts/nginx/nginx.conf
@@ -32,7 +32,7 @@ http {
         error_page 502 /static/html/500.html;
         error_page 503 /static/html/500.html;
 
-	if ($http_user_agent ~* (Amazonbot|meta-externalagent)) {
+	if ($http_user_agent ~* "(?:Amazonbot|meta-externalagent)") {
 	    return 444;
 	}