diff --git a/pkgs/servers/mastodon/default.nix b/pkgs/servers/mastodon/default.nix
index b8582f68ebc..1abedead87d 100644
--- a/pkgs/servers/mastodon/default.nix
+++ b/pkgs/servers/mastodon/default.nix
@@ -64,6 +64,7 @@ stdenv.mkDerivation rec {
       fi
       chmod -R u+w node_modules
       rake webpacker:compile
+      rails assets:precompile
     '';
 
     installPhase = ''