diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index b92a34f5f7b..b56d184d0d1 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7401,8 +7401,7 @@ in
 
   redir = callPackage ../tools/networking/redir { };
 
-  # failed to build websocket-driver gem with ruby 2.6, so sticking to 2.5 for now
-  redmine = callPackage ../applications/version-management/redmine { ruby = pkgs.ruby_2_5; };
+  redmine = callPackage ../applications/version-management/redmine { };
 
   redsocks = callPackage ../tools/networking/redsocks { };