diff --git a/.github/workflows/extension.yml b/.github/workflows/extension.yml
deleted file mode 100644
index 6b525cd38..000000000
--- a/.github/workflows/extension.yml
+++ /dev/null
@@ -1,42 +0,0 @@
-name: extension
-
-permissions: {}
-
-on:
-  push:
-    tags:
-      - '*_*_*'
-
-jobs:
-  extension:
-    runs-on: ubuntu-24.04
-    env:
-      BLENDER_ARCHIVE_URL: https://mirrors.ocf.berkeley.edu/blender/release/Blender4.2/blender-4.2.0-linux-x64.tar.xz
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          submodules: recursive
-      - name: Cache archive
-        id: cache-archive
-        uses: actions/cache@v4
-        with:
-          path: blender.tar.xz
-          key: ${{ env.BLENDER_ARCHIVE_URL }}-archive-1
-      - name: Download archive
-        if: steps.cache-archive.outputs.cache-hit != 'true'
-        run: curl --fail --location --show-error --retry 5 --retry-all-errors "$BLENDER_ARCHIVE_URL" -o blender.tar.xz || true
-      - name: Build Extension
-        run: |
-          mkdir -p ~/.local/blender
-          if ! tar xf blender.tar.xz -C ~/.local/blender --strip-components=1; then
-            echo "Please upgrade archive URL"
-            exit 0
-          fi
-          export PATH="$HOME/.local/blender:$PATH"
-          hash -r
-          ./tools/build_extension.sh
-      - name: Save Extension
-        uses: actions/upload-artifact@v4
-        with:
-          name: Extension
-          path: extension_output
diff --git a/.github/workflows/readme.yml b/.github/workflows/readme.yml
index a241bbd92..cb9c3f24a 100644
--- a/.github/workflows/readme.yml
+++ b/.github/workflows/readme.yml
@@ -27,7 +27,6 @@ jobs:
           git checkout README
           cp -fr ../.github .
           rm .github/workflows/gh-pages.yml
-          rm .github/workflows/extension.yml
           rm .github/workflows/readme.yml
           rm .github/workflows/release.yml
           rm .github/workflows/test.yml
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 040914c89..191e4737c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -11,12 +11,25 @@ on:
 jobs:
   release:
     runs-on: ubuntu-24.04
+    env:
+      BLENDER_ARCHIVE_URL: https://mirrors.ocf.berkeley.edu/blender/release/Blender4.2/blender-4.2.0-linux-x64.tar.xz
     steps:
       - name: Install package
         run: |
           sudo apt-get update -qq
           sudo apt-get dist-upgrade -y
           sudo apt-get install -y advancecomp blender curl git python3 python3-numpy ruby shellcheck xz-utils
+      - name: Cache archive
+        id: cache-archive
+        uses: actions/cache@v4
+        with:
+          path: blender.tar.xz
+          key: ${{ env.BLENDER_ARCHIVE_URL }}-archive-1
+      - name: Download archive
+        if: steps.cache-archive.outputs.cache-hit != 'true'
+        run: |
+          curl --fail --location --show-error --retry 5 --retry-all-errors "$BLENDER_ARCHIVE_URL" -o blender.tar.xz
+          test "$(md5sum blender.tar.xz)" = "d4555313745524a6add308001e3198cfa  blender.tar.xz"
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
diff --git a/tools/release.sh b/tools/release.sh
index 91d26f22d..05279680e 100755
--- a/tools/release.sh
+++ b/tools/release.sh
@@ -40,6 +40,23 @@ for postfix in "$release_postfix" "$tag_name"; do
   cp "${work_dir}/${prefix_name}-${postfix}.zip" .
 done
 
+mkdir -p ~/.local/blender
+if ! tar xf blender.tar.xz -C ~/.local/blender --strip-components=1; then
+  echo "Please upgrade archive URL"
+  exit 1
+fi
+export PATH="$HOME/.local/blender:$PATH"
+hash -r
+test "$HOME/.local/blender/blender" = "$(command -v blender)"
+./tools/build_extension.sh
+extension_path=$(find extension_output -name "vrm_*_*.zip" | sort | head -n 1)
+if [ ! -f "$extension_path" ]; then
+  echo "No extension output"
+  exit 1
+fi
+rm -fr ~/.local/blender
+hash -r
+
 if ! curl \
   --fail \
   --show-error \
@@ -67,7 +84,23 @@ if ! curl \
   --header "Authorization: Bearer $GITHUB_TOKEN" \
   --header "Content-Type: application/zip" \
   --data-binary "@${prefix_name}-${tag_name}.zip" \
-  "${upload_url}?name=${prefix_name}-${tag_name}.zip&label=VRM%20Add-on%20for%20Blender%20${version}%20(zip)"; then
+  "${upload_url}?name=${prefix_name}-${tag_name}.zip&label=(Blender%202.93%20-%204.1)%20VRM%20Add-on%20for%20Blender%20${version}%20(zip)"; then
+
+  cat release_upload.json
+  exit 1
+fi
+
+if ! curl \
+  --fail \
+  --show-error \
+  --location \
+  --output release_upload.json \
+  --request POST \
+  --header 'Accept: application/vnd.github.v3+json' \
+  --header "Authorization: Bearer $GITHUB_TOKEN" \
+  --header "Content-Type: application/zip" \
+  --data-binary "@${extension_path}" \
+  "${upload_url}?name=${prefix_name}-Extension-${tag_name}.zip&label=(Blender%204.2%20or%20later)%20VRM%20Add-on%20for%20Blender%20Extension%20${version}%20(zip)"; then
 
   cat release_upload.json
   exit 1