diff --git a/nixos/modules/services/mail/public-inbox.nix b/nixos/modules/services/mail/public-inbox.nix
index 14a2ab48fa25..98063e0331bd 100644
--- a/nixos/modules/services/mail/public-inbox.nix
+++ b/nixos/modules/services/mail/public-inbox.nix
@@ -455,7 +455,7 @@ in
           after = [ "public-inbox-init.service" "public-inbox-watch.service" ];
           requires = [ "public-inbox-init.service" ];
           serviceConfig = {
-            BindPathsReadOnly =
+            BindReadOnlyPaths =
               map (c: c.dir) (lib.attrValues cfg.settings.coderepo);
             ExecStart = escapeShellArgs (
               [ "${cfg.package}/bin/public-inbox-httpd" ] ++