diff --git a/pkgs/servers/mastodon/default.nix b/pkgs/servers/mastodon/default.nix
index f1f96a2d0b4b..54e0c8624d94 100644
--- a/pkgs/servers/mastodon/default.nix
+++ b/pkgs/servers/mastodon/default.nix
@@ -36,14 +36,15 @@ stdenv.mkDerivation rec {
     pname = "${pname}-modules";
     inherit src version;
 
-    yarnOfflineCache = callPackage ./yarn.nix {
-      inherit version src;
+    yarnOfflineCache = yarn-berry.fetchYarnBerryDeps {
+      inherit src;
       hash = yarnHash;
     };
 
     nativeBuildInputs = [
       nodejs-slim
       yarn-berry
+      yarn-berry.yarnBerryConfigHook
       mastodonGems
       mastodonGems.wrappedRuby
       brotli
@@ -56,38 +57,28 @@ stdenv.mkDerivation rec {
     buildPhase = ''
       runHook preBuild
 
-      export HOME=$PWD
-      export YARN_ENABLE_TELEMETRY=0
-      export npm_config_nodedir=${nodejs-slim}
       export SECRET_KEY_BASE_DUMMY=1
 
-      mkdir -p ~/.yarn/berry
-      ln -s $yarnOfflineCache ~/.yarn/berry/cache
-
-      yarn install --immutable --immutable-cache
-
-      patchShebangs ~/bin
-      patchShebangs ~/node_modules
+      patchShebangs bin
 
       bundle exec rails assets:precompile
 
-      yarn cache clean --all
-      rm -rf ~/node_modules/.cache
+      rm -rf node_modules/.cache
 
       # Remove workspace "package" as it contains broken symlinks
       # See https://github.com/NixOS/nixpkgs/issues/380366
-      rm -rf ~/node_modules/@mastodon
+      rm -rf node_modules/@mastodon
 
       # Remove execute permissions
-      find ~/public/assets -type f ! -perm 0555 \
+      find public/assets -type f ! -perm 0555 \
         -exec chmod 0444 {} ';'
 
       # Create missing static gzip and brotli files
-      find ~/public/assets -type f -regextype posix-extended -iregex '.*\.(css|html|js|json|svg)' \
+      find public/assets -type f -regextype posix-extended -iregex '.*\.(css|html|js|json|svg)' \
         -exec gzip --best --keep --force {} ';' \
         -exec brotli --best --keep {} ';'
-      gzip --best --keep ~/public/packs/report.html
-      brotli --best --keep ~/public/packs/report.html
+      gzip --best --keep public/packs/report.html
+      brotli --best --keep public/packs/report.html
 
       runHook postBuild
     '';
diff --git a/pkgs/servers/mastodon/source.nix b/pkgs/servers/mastodon/source.nix
index 58563cc2a07a..15a415f21ba3 100644
--- a/pkgs/servers/mastodon/source.nix
+++ b/pkgs/servers/mastodon/source.nix
@@ -18,5 +18,5 @@ in
 })
 // {
   inherit version;
-  yarnHash = "sha256-e5c04M6XplAgaVyldU5HmYMYtY3MAWs+a8Z/BGSyGBg=";
+  yarnHash = "sha256-IC4d/skIHEzJPuKlq4rMAqV+ydqquA6toq4WWCfuDxo=";
 }
diff --git a/pkgs/servers/mastodon/update.sh b/pkgs/servers/mastodon/update.sh
index b9e3c6453f6d..330e53676b7a 100755
--- a/pkgs/servers/mastodon/update.sh
+++ b/pkgs/servers/mastodon/update.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#! nix-shell -i bash -p bundix coreutils diffutils nix-prefetch-github gnused jq prefetch-yarn-deps
+#! nix-shell -i bash -p bundix coreutils diffutils nix-prefetch-github gnused jq yarn-berry_4.yarn-berry-fetcher
 set -e
 
 OWNER=mastodon
@@ -110,5 +110,6 @@ echo "Creating gemset.nix"
 bundix --lockfile="$SOURCE_DIR/Gemfile.lock" --gemfile="$SOURCE_DIR/Gemfile"
 echo "" >> gemset.nix  # Create trailing newline to please EditorConfig checks
 
-echo "Required manual update of yarn-hash"
-exit 1
+echo "Updating yarnHash"
+YARN_HASH="$(yarn-berry-fetcher prefetch "$SOURCE_DIR/yarn.lock" 2>/dev/null)"
+sed -i "s;sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=;$YARN_HASH;g" source.nix
diff --git a/pkgs/servers/mastodon/yarn.nix b/pkgs/servers/mastodon/yarn.nix
deleted file mode 100644
index e38eb739737f..000000000000
--- a/pkgs/servers/mastodon/yarn.nix
+++ /dev/null
@@ -1,37 +0,0 @@
-{
-  stdenvNoCC,
-  yarn-berry,
-  cacert,
-  version,
-  src,
-  hash,
-}:
-stdenvNoCC.mkDerivation {
-  pname = "yarn-deps";
-  inherit version src;
-
-  nativeBuildInputs = [
-    yarn-berry
-  ];
-
-  dontInstall = true;
-
-  NODE_EXTRA_CA_CERTS = "${cacert}/etc/ssl/certs/ca-bundle.crt";
-
-  buildPhase = ''
-    export HOME=$(mktemp -d)
-    export YARN_ENABLE_TELEMETRY=0
-
-    yarn config set --json supportedArchitectures.os '[ "linux" ]'
-    yarn config set --json supportedArchitectures.cpu '[ "arm64", "x64", "ia32" ]'
-
-    cache="$(yarn config get cacheFolder)"
-    yarn install --immutable --mode skip-build
-
-    mkdir -p $out
-    cp -r $cache/* $out/
-  '';
-
-  outputHash = hash;
-  outputHashMode = "recursive";
-}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index bb5d067c88fd..428a72e02e45 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11961,7 +11961,7 @@ with pkgs;
     nodejs-slim = nodejs-slim_22;
     python3 = python311;
     ruby = ruby_3_3;
-    yarn-berry = yarn-berry.override { nodejs = nodejs-slim_22; };
+    yarn-berry = yarn-berry_4.override { nodejs = nodejs-slim_22; };
   };
 
   micro-full = micro.wrapper.override {