diff --git a/app/webserver.py b/app/webserver.py
index 6166fe6..c9da100 100644
--- a/app/webserver.py
+++ b/app/webserver.py
@@ -382,6 +382,8 @@ class AnnotationHandler(tornado.web.RequestHandler):
 
         if extension == "svg":
             self.set_header("Content-Type", "image/svg+xml")
+            self.set_header("Cache-Control", "max-age=31536000, immutable")
+            
             self.write(annotation.get_as_svg())
         elif extension == "mp3":
             self.set_header("Content-Type", "audio/mp3")