diff --git a/calendar/service.go b/calendar/service.go
index ca4aa9d..17a882d 100644
--- a/calendar/service.go
+++ b/calendar/service.go
@@ -48,6 +48,7 @@ func (srv Service) Load() error {
 		if err != nil {
 			panic(err)
 		}
+		c.Header("Content-Type", "text/calendar; charset=utf-8")
 		c.String(200, ics)
 	})