diff --git a/nixos/modules/services/misc/redmine.nix b/nixos/modules/services/misc/redmine.nix
index 4b2f3bbb7627..5d91468753b4 100644
--- a/nixos/modules/services/misc/redmine.nix
+++ b/nixos/modules/services/misc/redmine.nix
@@ -155,7 +155,7 @@ in {
       environment.HOME = "${pkgs.redmine}/share/redmine";
       environment.REDMINE_LANG = "en";
       environment.GEM_HOME = "${pkgs.redmine}/share/redmine/vendor/bundle/ruby/1.9.1";
-      environment.GEM_PATH = "${rubyPackages.bundler}/lib/ruby/gems/1.9";
+      environment.GEM_PATH = "${bundler}/${bundler.ruby.gemPath}";
       path = with pkgs; [
         imagemagickBig
         subversion