diff --git a/e.hh b/e.hh
index f736a4a..bf7af12 100644
--- a/e.hh
+++ b/e.hh
@@ -1,7 +1,7 @@
 <?hh // strict
 
 <<__Entrypoint>>
-function main() {
+function main(): void {
   while(true) {
     echo 'e';
   }