diff --git a/nixos/modules/services/misc/redmine.nix b/nixos/modules/services/misc/redmine.nix
index bf9a6914a48..8bd687d0838 100644
--- a/nixos/modules/services/misc/redmine.nix
+++ b/nixos/modules/services/misc/redmine.nix
@@ -66,7 +66,7 @@ in
         type = types.package;
         default = pkgs.redmine;
         description = "Which Redmine package to use.";
-        example = "pkgs.redmine.override { ruby = pkgs.ruby_2_4; }";
+        example = "pkgs.redmine.override { ruby = pkgs.ruby_2_7; }";
       };
 
       user = mkOption {