diff --git a/nixos/modules/services/mail/opensmtpd.nix b/nixos/modules/services/mail/opensmtpd.nix
index c54fd1950cfb..3b493d2015dc 100644
--- a/nixos/modules/services/mail/opensmtpd.nix
+++ b/nixos/modules/services/mail/opensmtpd.nix
@@ -61,7 +61,7 @@ in {
       };
 
       procPackages = mkOption {
-        type = types.listOf types.path;
+        type = types.listOf types.package;
         default = [];
         description = ''
           Packages to search for filters, tables, queues, and schedulers.