diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 2831c93..03133d7 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -49,6 +49,7 @@ jobs:
 
   validate-blog:
     if: startsWith(github.head_ref, 'blog/')
+    needs: [build, lint, typecheck]
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
@@ -57,11 +58,9 @@ jobs:
           node-version-file: .node-version
           cache: npm
       - run: npm ci
-      - run: npm run validate-blog
-          - workin
+      - run: git diff --name-only | xargs npm run validate-blog --
 
   update-blogmeta:
-    if: startsWith(github.head_ref, 'blog/')
     needs: [validate-blog]
     permissions:
       pages: write
@@ -73,12 +72,12 @@ jobs:
           node-version-file: .node-version
           cache: npm
       - run: npm ci
-      - run: git diff --name-only | xargs npx ts-node --esm ./tools/update-blogmeta.ts
+      - run: git diff --name-only | xargs npm run update-blogmeta --
       - run: |
           git config --local user.email "github-actions[bot]@users.noreply.github.com"
           git config --local user.name "github-actions[bot]"
           git add .
-          git commit -m "[Bot] Update Blog Meta"
+          git commit -m "[Bot] Update blog meta"
           git push origin ${{github.head_ref}}
 
   deploy:
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 2296e09..e90ef3d 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -2,6 +2,5 @@
   "editor.formatOnSave": true,
   "editor.formatOnPaste": true,
   "editor.defaultFormatter": "esbenp.prettier-vscode",
-  "prettier.documentSelectors": ["**/*.astro"],
-  "svg.preview.background": "transparent"
+  "prettier.documentSelectors": ["**/*.astro"]
 }
diff --git a/package.json b/package.json
index de1b451..ca38648 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,8 @@
     "typecheck": "astro check && tsc --noEmit",
     "lint": "prettier --check \"./**/*.{ts,tsx,astro,json}\"",
     "format": "prettier --write \"./**/*.{ts,tsx,astro,json}\"",
-    "validate-blog": "git diff --name-only | xargs npx ts-node --esm tools/validate-blog.ts"
+    "validate-blog": "ts-node --esm tools/validate-blog.ts",
+    "update-blogmeta": "ts-node --esm tools/update-blogmeta.ts"
   },
   "dependencies": {
     "@astrojs/check": "^0.3.1",
diff --git a/src/assets/icons/blog/default_user.svg b/src/assets/icons/blog/default_user.svg
new file mode 100644
index 0000000..f0a80fa
--- /dev/null
+++ b/src/assets/icons/blog/default_user.svg
@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
+    <rect width="64" height="64" fill="gray" />
+    <circle cx="32" cy="64" r="24" fill="silver" />
+    <circle cx="32" cy="28" r="18" fill="silver" />
+</svg>
\ No newline at end of file
diff --git a/src/components/blog/icon/AuthorIcon.astro b/src/components/blog/icon/AuthorIcon.astro
index 43bccf6..2e93e91 100644
--- a/src/components/blog/icon/AuthorIcon.astro
+++ b/src/components/blog/icon/AuthorIcon.astro
@@ -6,35 +6,35 @@ type Props = CollectionEntry<'authors'>['data'] & { size: number }
 
 const { size, ...author } = Astro.props
 
-const image = author.image
-  ? author.image
-  : author.github
-  ? ({
-      type: 'external-url',
-      url: `https://github.com/${author.github}.png`,
-    } as const)
-  : undefined
+const image =
+  author.image.type === 'svg' &&
+  author.image.name === 'default_user' &&
+  author.github
+    ? ({
+        type: 'external-url',
+        url: `https://github.com/${author.github}.png`,
+      } as const)
+    : author.image
 ---
 
 {
-  image &&
-    (image.type === 'svg' ? (
-      <Icon
-        name={image.name}
-        alt={`${image.name} のアイコン`}
-        class="aspect-square rounded-full"
-        height={size}
-        width={size}
-        isBlog
-      />
-    ) : image.type === 'external-url' ? (
-      <img
-        src={image.url}
-        height={size}
-        width={size}
-        class="aspect-square rounded-full"
-      />
-    ) : (
-      unreachable(image)
-    ))
+  image.type === 'svg' ? (
+    <Icon
+      name={image.name}
+      alt={`${image.name} のアイコン`}
+      class="aspect-square rounded-full"
+      height={size}
+      width={size}
+      isBlog
+    />
+  ) : image.type === 'external-url' ? (
+    <img
+      src={image.url}
+      height={size}
+      width={size}
+      class="aspect-square rounded-full"
+    />
+  ) : (
+    unreachable(image)
+  )
 }
diff --git a/src/content/config.ts b/src/content/config.ts
index 465d721..6ec3304 100644
--- a/src/content/config.ts
+++ b/src/content/config.ts
@@ -42,7 +42,7 @@ const authorsCollection = defineCollection({
           url: z.string().url(),
         }),
       ])
-      .optional(),
+      .default({ type: 'svg', name: 'default_user' }),
   }),
 })
 
diff --git a/src/pages/blog/authors/[slug]/index.astro b/src/pages/blog/authors/[slug]/index.astro
index fb50cd4..5f523dd 100644
--- a/src/pages/blog/authors/[slug]/index.astro
+++ b/src/pages/blog/authors/[slug]/index.astro
@@ -4,6 +4,7 @@ import BlogTitle from '@/components/blog/BlogTitle.astro'
 import AuthorAboutSection from '@/components/blog/author/AuthorAboutSection.astro'
 import AuthorIcon from '@/components/blog/icon/AuthorIcon.astro'
 import BlogLayout from '@/layouts/BlogLayout.astro'
+import { unreachable } from '@/utils/unreachable'
 import { getCollection } from 'astro:content'
 export async function getStaticPaths() {
   const authorEntries = await getCollection('authors')
@@ -16,13 +17,15 @@ export async function getStaticPaths() {
 const { author } = Astro.props
 const blogEntries = await getCollection('blogs')
 const ogpPath =
-  author.data.image === undefined && author.data.github !== undefined
+  author.data.image.type === 'svg' &&
+  author.data.image.name === 'default_user' &&
+  author.data.github
     ? `https://github.com/${author.data.github}.png`
-    : author.data.image?.type === 'svg'
+    : author.data.image.type === 'svg'
     ? `/author/${author.id}/ogp.png`
-    : author.data.image?.type === 'external-url'
+    : author.data.image.type === 'external-url'
     ? author.data.image.url
-    : undefined
+    : unreachable(author.data.image)
 
 const isShowAboutSection = author.data.description || author.data.github
 ---
@@ -35,13 +38,9 @@ const isShowAboutSection = author.data.description || author.data.github
   summarySize={ogpPath === undefined ? undefined : 'summary'}
 >
   <BlogTitle title={author.data.name} background="white">
-    {
-      (author.data.github || author.data.image) && (
-        <Fragment slot="icon">
-          <AuthorIcon {...author.data} size={95} />
-        </Fragment>
-      )
-    }
+    <Fragment slot="icon">
+      <AuthorIcon {...author.data} size={93} />
+    </Fragment>
   </BlogTitle>
   {isShowAboutSection && <AuthorAboutSection author={author.data} />}
   <main class="flex flex-col h-full">
diff --git a/src/pages/blog/authors/[slug]/ogp.png.ts b/src/pages/blog/authors/[slug]/ogp.png.ts
index 3da9e7b..fc951bc 100644
--- a/src/pages/blog/authors/[slug]/ogp.png.ts
+++ b/src/pages/blog/authors/[slug]/ogp.png.ts
@@ -6,7 +6,12 @@ export async function getStaticPaths() {
   const authors = await getCollection('authors')
 
   return authors
-    .filter((author) => author.data.image?.type === 'svg')
+    .filter(
+      (author) =>
+        author.data.image.type !== 'svg' ||
+        author.data.image.name !== 'default_user' ||
+        !author.data.github,
+    )
     .map((author) => ({
       params: { slug: author.id },
       props: { author },