diff --git a/frontend/src/components/PostEmbed.tsx b/frontend/src/components/PostEmbed.tsx
index c375ca1..d5e7cba 100644
--- a/frontend/src/components/PostEmbed.tsx
+++ b/frontend/src/components/PostEmbed.tsx
@@ -18,17 +18,26 @@ export default (({ post }: Props) => {
   {
   case 'nicovideo.jp':
     {
-      const [videoId] = url.pathname.match (/(?<=\/watch\/)[a-zA-Z0-9]+?(?=\/|$)/)!
+      const mVideoId = url.pathname.match (/(?<=\/watch\/)[a-zA-Z0-9]+?(?=\/|$)/)
+      if (!(mVideoId))
+	break
+      const [videoId] = mVideoId
       return <NicoViewer id={videoId} width={640} height={360}/>
     }
   case 'twitter.com':
   case 'x.com':
-    const [userId] = url.pathname.match (/(?<=\/)[^\/]+?(?=\/|$|\?)/)!
-    const [statusId] = url.pathname.match (/(?<=\/status\/)\d+?(?=\/|$|\?)/)!
+    const mUserId = url.pathname.match (/(?<=\/)[^\/]+?(?=\/|$|\?)/)
+    const mStatusId = url.pathname.match (/(?<=\/status\/)\d+?(?=\/|$|\?)/)
+    if (!(mUserId) || !(mStatusId))
+      break
+    const [userId] = mUserId
+    const [statusId] = mStatusId
     return <TwitterEmbed userId={userId} statusId={statusId}/>
   case 'youtube.com':
     {
-      const videoId = url.searchParams.get ('v')!
+      const videoId = url.searchParams.get ('v')
+      if (!(videoId))
+	break
       return (
 	  <YoutubeEmbed videoId={videoId} opts={{ playerVars: {
 	      playsinline:  1,