diff --git a/tools/dep_updaters/update-ada.sh b/tools/dep_updaters/update-ada.sh
index a6fa2464728b97..9f4f779b6ae02b 100755
--- a/tools/dep_updaters/update-ada.sh
+++ b/tools/dep_updaters/update-ada.sh
@@ -54,8 +54,8 @@ rm "$ADA_ZIP"
 
 curl -sL -o "$ADA_LICENSE" "https://raw.githubusercontent.com/ada-url/ada/HEAD/LICENSE-MIT"
 
-echo "Replacing existing ada (except GYP build files)"
-mv "$DEPS_DIR/ada/"*.gyp "$DEPS_DIR/ada/README.md" "$WORKSPACE/"
+echo "Replacing existing ada (except GYP and GN build files)"
+mv "$DEPS_DIR/ada/"*.gyp "$DEPS_DIR/ada/"*.gn "$DEPS_DIR/ada/"*.gni "$DEPS_DIR/ada/README.md" "$WORKSPACE/"
 rm -rf "$DEPS_DIR/ada"
 mv "$WORKSPACE" "$DEPS_DIR/ada"
 
diff --git a/tools/dep_updaters/update-brotli.sh b/tools/dep_updaters/update-brotli.sh
index c7e8979d178526..90b65ed31a284b 100755
--- a/tools/dep_updaters/update-brotli.sh
+++ b/tools/dep_updaters/update-brotli.sh
@@ -60,12 +60,15 @@ mv "brotli-$NEW_VERSION" "brotli"
 echo "Copying existing gyp file"
 cp "$DEPS_DIR/brotli/brotli.gyp" "$WORKSPACE/brotli"
 
+echo "Copying existing GN files"
+cp "$DEPS_DIR/brotli/"*.gn "$DEPS_DIR/brotli/"*.gni "$WORKSPACE/brotli"
+
 echo "Deleting existing brotli"
 rm -rf "$DEPS_DIR/brotli"
 mkdir "$DEPS_DIR/brotli"
 
 echo "Update c and LICENSE"
-mv "$WORKSPACE/brotli/c" "$WORKSPACE/brotli/LICENSE" "$WORKSPACE/brotli/brotli.gyp" "$DEPS_DIR/brotli"
+mv "$WORKSPACE/brotli/"*.gn "$WORKSPACE/brotli/"*.gni "$WORKSPACE/brotli/c" "$WORKSPACE/brotli/LICENSE" "$WORKSPACE/brotli/brotli.gyp" "$DEPS_DIR/brotli"
 
 # Update the version number on maintaining-dependencies.md
 # and print the new version as the last line of the script as we need
diff --git a/tools/dep_updaters/update-c-ares.sh b/tools/dep_updaters/update-c-ares.sh
index 4a679105405c2d..5081a74545dbf2 100755
--- a/tools/dep_updaters/update-c-ares.sh
+++ b/tools/dep_updaters/update-c-ares.sh
@@ -56,10 +56,11 @@ mv "c-ares-$NEW_VERSION" cares
 echo "Removing tests"
 rm -rf "$WORKSPACE/cares/test"
 
-echo "Copying existing .gitignore, config and gyp files"
+echo "Copying existing .gitignore, config, gyp and gn files"
 cp -R "$DEPS_DIR/cares/config" "$WORKSPACE/cares"
 cp "$DEPS_DIR/cares/.gitignore" "$WORKSPACE/cares"
 cp "$DEPS_DIR/cares/cares.gyp" "$WORKSPACE/cares"
+cp "$DEPS_DIR/cares/"*.gn "$DEPS_DIR/cares/"*.gni "$WORKSPACE/cares"
 
 echo "Replacing existing c-ares"
 rm -rf "$DEPS_DIR/cares"
diff --git a/tools/dep_updaters/update-libuv.sh b/tools/dep_updaters/update-libuv.sh
index 83c285ecaa2000..c2524ddbf0dd66 100755
--- a/tools/dep_updaters/update-libuv.sh
+++ b/tools/dep_updaters/update-libuv.sh
@@ -59,8 +59,8 @@ gzip -dc "$LIBUV_TARBALL" | tar xf -
 rm "$LIBUV_TARBALL"
 mv libuv-libuv-* uv
 
-echo "Replacing existing libuv (except GYP build files)"
-mv "$DEPS_DIR/uv/"*.gyp "$DEPS_DIR/uv/"*.gypi "$WORKSPACE/uv/"
+echo "Replacing existing libuv (except GYP and GN build files)"
+mv "$DEPS_DIR/uv/"*.gyp "$DEPS_DIR/uv/"*.gypi "$DEPS_DIR/uv/"*.gn "$DEPS_DIR/uv/"*.gni "$WORKSPACE/uv/"
 rm -rf "$DEPS_DIR/uv"
 mv "$WORKSPACE/uv" "$DEPS_DIR/"
 
diff --git a/tools/dep_updaters/update-llhttp.sh b/tools/dep_updaters/update-llhttp.sh
index c9462748775287..739819e1a45b69 100755
--- a/tools/dep_updaters/update-llhttp.sh
+++ b/tools/dep_updaters/update-llhttp.sh
@@ -45,6 +45,9 @@ trap cleanup INT TERM EXIT
 
 cd "$WORKSPACE"
 
+echo "Replacing existing llhttp (except GYP and GN build files)"
+mv "$DEPS_DIR/llhttp/"*.gn "$DEPS_DIR/llhttp/"*.gni "$WORKSPACE/"
+
 if echo "$NEW_VERSION" | grep -qs "/" ; then # Download a release
   REPO="git@github.com:$NEW_VERSION.git"
   BRANCH=$2
@@ -74,6 +77,8 @@ else
   cp -a "llhttp-release-v$NEW_VERSION" "$DEPS_DIR/llhttp"
 fi
 
+mv "$WORKSPACE/"*.gn "$WORKSPACE/"*.gni "$DEPS_DIR/llhttp"
+
 # Update the version number on maintaining-dependencies.md
 # and print the new version as the last line of the script as we need
 # to add it to $GITHUB_ENV variable
diff --git a/tools/dep_updaters/update-nghttp2.sh b/tools/dep_updaters/update-nghttp2.sh
index 4c375c979691f6..ccb36caae13d4d 100755
--- a/tools/dep_updaters/update-nghttp2.sh
+++ b/tools/dep_updaters/update-nghttp2.sh
@@ -73,6 +73,9 @@ cp "$DEPS_DIR/nghttp2/lib/includes/config.h" "$WORKSPACE/nghttp2/lib/includes"
 echo "Copying existing gyp files"
 cp "$DEPS_DIR/nghttp2/nghttp2.gyp" "$WORKSPACE/nghttp2"
 
+echo "Copying existing GN files"
+cp "$DEPS_DIR/nghttp2/"*.gn "$DEPS_DIR/nghttp2/"*.gni "$WORKSPACE/nghttp2"
+
 echo "Replacing existing nghttp2"
 rm -rf "$DEPS_DIR/nghttp2"
 mv "$WORKSPACE/nghttp2" "$DEPS_DIR/"
diff --git a/tools/dep_updaters/update-postject.sh b/tools/dep_updaters/update-postject.sh
index 55c0de21a7f1b1..671bcd5a3a9ef6 100755
--- a/tools/dep_updaters/update-postject.sh
+++ b/tools/dep_updaters/update-postject.sh
@@ -7,13 +7,14 @@
 
 set -ex
 
-ROOT=$(cd "$(dirname "$0")/../.." && pwd)
-[ -z "$NODE" ] && NODE="$ROOT/out/Release/node"
+BASE_DIR=$(cd "$(dirname "$0")/../.." && pwd)
+DEPS_DIR="$BASE_DIR/deps"
+[ -z "$NODE" ] && NODE="$BASE_DIR/out/Release/node"
 [ -x "$NODE" ] || NODE=$(command -v node)
-NPM="$ROOT/deps/npm/bin/npm-cli.js"
+NPM="$BASE_DIR/deps/npm/bin/npm-cli.js"
 
 # shellcheck disable=SC1091
-. "$ROOT/tools/dep_updaters/utils.sh"
+. "$BASE_DIR/tools/dep_updaters/utils.sh"
 
 NEW_VERSION=$("$NODE" "$NPM" view postject dist-tags.latest)
 CURRENT_VERSION=$("$NODE" -p "require('./test/fixtures/postject-copy/node_modules/postject/package.json').version")
@@ -21,21 +22,34 @@ CURRENT_VERSION=$("$NODE" -p "require('./test/fixtures/postject-copy/node_module
 # This function exit with 0 if new version and current version are the same
 compare_dependency_version "postject" "$NEW_VERSION" "$CURRENT_VERSION"
 
-cd "$( dirname "$0" )/../.." || exit
-rm -rf test/fixtures/postject-copy
-mkdir test/fixtures/postject-copy
-cd test/fixtures/postject-copy || exit
+echo "Making temporary workspace..."
+
+WORKSPACE=$(mktemp -d 2> /dev/null || mktemp -d -t 'tmp')
+
+cleanup () {
+  EXIT_CODE=$?
+  [ -d "$WORKSPACE" ] && rm -rf "$WORKSPACE"
+  exit $EXIT_CODE
+}
+
+trap cleanup INT TERM EXIT
+
+cd "$WORKSPACE"
+
+echo "Installing postject npm package..."
 
 "$NODE" "$NPM" init --yes
 
 "$NODE" "$NPM" install --no-bin-links --ignore-scripts "postject@$NEW_VERSION"
 
-# TODO(RaisinTen): Replace following with $WORKSPACE
-cd ../../..
-rm -rf deps/postject
-mkdir deps/postject
-cp test/fixtures/postject-copy/node_modules/postject/LICENSE deps/postject
-cp test/fixtures/postject-copy/node_modules/postject/dist/postject-api.h deps/postject
+echo "Replacing existing postject (except GN build files)"
+
+mv "$DEPS_DIR/postject/"*.gn "$DEPS_DIR/postject/"*.gni "$WORKSPACE/"
+rm -rf "$DEPS_DIR/postject"
+mkdir "$DEPS_DIR/postject"
+mv "$WORKSPACE/"*.gn "$WORKSPACE/"*.gni "$DEPS_DIR/postject"
+mv "$WORKSPACE/node_modules/postject/LICENSE" "$DEPS_DIR/postject"
+mv "$WORKSPACE/node_modules/postject/dist/postject-api.h" "$DEPS_DIR/postject"
 
 # Update the version number on maintaining-dependencies.md
 # and print the new version as the last line of the script as we need
diff --git a/tools/dep_updaters/update-simdutf.sh b/tools/dep_updaters/update-simdutf.sh
index ce22798006e546..bb4ea276548ed1 100755
--- a/tools/dep_updaters/update-simdutf.sh
+++ b/tools/dep_updaters/update-simdutf.sh
@@ -54,8 +54,8 @@ rm ./*_demo.cpp
 
 curl -sL -o "$SIMDUTF_LICENSE" "https://raw.githubusercontent.com/simdutf/simdutf/HEAD/LICENSE-MIT"
 
-echo "Replacing existing simdutf (except GYP build files)"
-mv "$DEPS_DIR/simdutf/"*.gyp "$DEPS_DIR/simdutf/README.md" "$WORKSPACE/"
+echo "Replacing existing simdutf (except GYP and GN build files)"
+mv "$DEPS_DIR/simdutf/"*.gyp "$DEPS_DIR/simdutf/"*.gn "$DEPS_DIR/simdutf/"*.gni "$DEPS_DIR/simdutf/README.md" "$WORKSPACE/"
 rm -rf "$DEPS_DIR/simdutf"
 mv "$WORKSPACE" "$DEPS_DIR/simdutf"
 
diff --git a/tools/dep_updaters/update-uvwasi.sh b/tools/dep_updaters/update-uvwasi.sh
index c36a7377bf44bc..8b4070cb336565 100755
--- a/tools/dep_updaters/update-uvwasi.sh
+++ b/tools/dep_updaters/update-uvwasi.sh
@@ -54,13 +54,17 @@ log_and_verify_sha256sum "uvwasi" "$UVWASI_ZIP.zip"
 
 echo "Moving existing GYP build file"
 mv "$DEPS_DIR/uvwasi/"*.gyp "$WORKSPACE/"
+
+echo "Moving existing GN build file"
+mv "$DEPS_DIR/uvwasi/"*.gn "$DEPS_DIR/uvwasi/"*.gni "$WORKSPACE/"
+
 rm -rf "$DEPS_DIR/uvwasi/"
 
 echo "Unzipping..."
 unzip "$UVWASI_ZIP.zip" -d "$DEPS_DIR/uvwasi/"
 rm "$UVWASI_ZIP.zip"
 
-mv "$WORKSPACE/"*.gyp "$DEPS_DIR/uvwasi/"
+mv "$WORKSPACE/"*.gyp "$WORKSPACE/"*.gn "$WORKSPACE/"*.gni "$DEPS_DIR/uvwasi/"
 cd "$DEPS_DIR/uvwasi/"
 
 echo "Copying new files to deps folder"