diff --git a/ops/nixos/bvm-prosody/default.nix b/ops/nixos/bvm-prosody/default.nix
index 449e763306..cfc11728f5 100644
--- a/ops/nixos/bvm-prosody/default.nix
+++ b/ops/nixos/bvm-prosody/default.nix
@@ -59,6 +59,8 @@ in {
     uploadHttp.domain = "upload.xmpp.lukegb.com";
 
     extraConfig = ''
+      archive_expires_after = "never"  -- keep messages forever
+
       proxy65_address = "xmpp.lukegb.com"
       proxy65_acl = { "lukegb.com" }