diff --git a/install/install.sh b/install/install.sh
index d3724550..d74f5cac 100644
--- a/install/install.sh
+++ b/install/install.sh
@@ -15,7 +15,7 @@ To disable this feature, checkout our sourcecode."
 mkdir -p /data/db /data/file ~/.hydro
 bash <(curl https://hydro.ac/nix.sh)
 export PATH=$HOME/.nix-profile/bin:$PATH
-nix-env -iA nixpkgs.nodejs nixpkgs.pm2 nixpkgs.yarn nixpkgs.esbuild nixpkgs.coreutils nixpkgs.bash nixpkgs.unzip nixpkgs.zip nixpkgs.diffutils nixpkgs.qrencode
+nix-env -iA nixpkgs.nodejs nixpkgs.coreutils nixpkgs.qrencode
 echo "扫码加入QQ群："
 echo https://qm.qq.com/cgi-bin/qm/qr\?k\=0aTZfDKURRhPBZVpTYBohYG6P6sxABTw | qrencode -o - -m 2 -t UTF8
 echo "// File created by Hydro install script\n" >/tmp/install.js
diff --git a/install/install.ts b/install/install.ts
index bbf088a0..4f866d78 100644
--- a/install/install.ts
+++ b/install/install.ts
@@ -183,6 +183,17 @@ const Steps = () => [
     {
         init: 'install.preparing',
         operations: [
+            () => {
+                if (CN) return;
+                // rollback mirrors
+                writeFileSync('/etc/nix/nix.conf', `substituters = https://cache.nixos.org/ https://nix.hydro.ac/cache
+trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydro.ac:EytfvyReWHFwhY9MCGimCIn46KQNfmv9y8E2NqlNfxQ=
+connect-timeout = 10`);
+                exec('nix-channel --del nixpkgs', { stdio: 'inherit' });
+                exec('nix-channel --add nixpkgs https://nixos.org/channels/nixpkgs-unstable', { stdio: 'inherit' });
+                exec('nix-channel --update', { stdio: 'inherit' });
+            },
+            'nix-env -iA nixpkgs.pm2 nixpkgs.yarn nixpkgs.esbuild nixpkgs.bash nixpkgs.unzip nixpkgs.zip nixpkgs.diffutils',
             () => {
                 // Not implemented yet
                 // if (fs.existsSync('/home/judge/src')) {
@@ -234,12 +245,12 @@ const Steps = () => [
             () => {
                 if (!CN) return;
                 try {
-                    exec('yarn config set registry https://registry.npmmirror.com/');
-                    exec('yarn global add hydrooj @hydrooj/ui-default @hydrooj/hydrojudge');
+                    exec('yarn config set registry https://registry.npmmirror.com/', { stdio: 'inherit' });
+                    exec('yarn global add hydrooj @hydrooj/ui-default @hydrooj/hydrojudge', { stdio: 'inherit' });
                 } catch (e) {
                     console.log('Failed to install from npmmirror, fallback to yarnpkg');
                 } finally {
-                    exec('yarn config set registry https://registry.yarnpkg.com');
+                    exec('yarn config set registry https://registry.yarnpkg.com', { stdio: 'inherit' });
                 }
                 try {
                     exec('yarn global add hydrooj @hydrooj/ui-default @hydrooj/hydrojudge');
@@ -353,7 +364,6 @@ async function main() {
         console.error(e);
         console.log('Cannot find the best mirror. Fallback to default.');
     }
-    return;
     const steps = Steps();
     for (let i = 0; i < steps.length; i++) {
         const step = steps[i];