diff --git a/shells/dodona.nix b/shells/dodona.nix
index f7562372..5c065df4 100644
--- a/shells/dodona.nix
+++ b/shells/dodona.nix
@@ -6,7 +6,7 @@ pkgs.mkShell {
     chromedriver
     libmysqlclient
     nodejs-12_x
-    ruby
+    ruby_2_7
     yarn
     zlib
     (