diff --git a/.github/workflows/package-size-comment.yml b/.github/workflows/package-size-comment.yml
index c03a956b..80b84fd4 100644
--- a/.github/workflows/package-size-comment.yml
+++ b/.github/workflows/package-size-comment.yml
@@ -70,6 +70,11 @@ jobs:
               && pullRequest.base.repo.full_name === expectedBaseRepository,
             )
 
+            if (matches.length === 0) {
+              core.info('The pull request closed or its head changed. Skipping the size comment.')
+              return
+            }
+
             if (matches.length !== 1) {
               core.setFailed(`Expected one open pull request for ${run.head_sha}, found ${matches.length}`)
               return
@@ -78,6 +83,7 @@ jobs:
             core.setOutput('number', matches[0].number)
 
       - name: Download package size report
+        if: steps.pull-request.outputs.number != ''
         uses: actions/download-artifact@v8
         with:
           name: package-size-report
@@ -88,6 +94,7 @@ jobs:
       # The artifact comes from a workflow run that may be a fork pull request.
       # Treat it as untrusted input and check it before it becomes a comment.
       - name: Validate package size report
+        if: steps.pull-request.outputs.number != ''
         env:
           COMMENT_PATH: ${{ runner.temp }}/package-size-comment.md
           EXPECTED_HEAD_SHA: ${{ github.event.workflow_run.head_sha }}
@@ -140,6 +147,7 @@ jobs:
           sed 's/@/@<!-- -->/g' "$report" > "$COMMENT_PATH"
 
       - name: Post comment on pull request
+        if: steps.pull-request.outputs.number != ''
         uses: actions/github-script@v9
         env:
           COMMENT_PATH: ${{ runner.temp }}/package-size-comment.md
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3ce59041..d980af96 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -43,7 +43,14 @@ jobs:
 
       - name: Plan release
         id: plan
-        run: node scripts/prepare-release.ts
+        run: |
+          # CI started before this workflow existed can finish after its merge.
+          if [ "$GITHUB_EVENT_NAME" = 'workflow_run' ] && [ ! -f scripts/prepare-release.ts ]; then
+            echo 'Skip CI for a commit that predates release automation.'
+            echo 'release=false' >> "$GITHUB_OUTPUT"
+          else
+            node scripts/prepare-release.ts
+          fi
 
   release:
     needs: prepare
diff --git a/scripts/check-release-channel.ts b/scripts/check-release-channel.ts
index b222882b..1a9e70a3 100644
--- a/scripts/check-release-channel.ts
+++ b/scripts/check-release-channel.ts
@@ -10,7 +10,7 @@ if (!distTag || !output)
 const names = ['@nuxt/scripts', '@nuxt/scripts-cli', '@nuxt/scripts-devtools']
 const currentVersions = await Promise.all(names.map(async (name) => {
   const response = await fetch(`https://registry.npmjs.org/${encodeURIComponent(name)}`, {
-    headers: { accept: 'application/vnd.npm.install-v1+json', 'cache-control': 'no-cache' },
+    headers: { 'accept': 'application/vnd.npm.install-v1+json', 'cache-control': 'no-cache' },
     signal: AbortSignal.timeout(30000),
   })
   if (!response.ok)