diff --git a/page_index.go b/page_index.go
index 7586d20fcdff3f8480862b051ad57d5a55f2f918..8ec8040a810692dc73f59f53bf906cfb864a8c2f 100644
--- a/page_index.go
+++ b/page_index.go
@@ -19,6 +19,8 @@ func pageIndex(ctx PageContext) http.Handler {
 				panic(err)
 			}
 		} else {
+			w.Header().Set("Vary", "Accept-Encoding")
+			w.Header().Set("Cache-Control", "public, max-age=31536000")
 			ctx.Images.ServeHTTP(w, r)
 		}
 	})