diff --git a/.cspell.json b/.cspell.json
index 57ebb38e..f4a0a683 100644
--- a/.cspell.json
+++ b/.cspell.json
@@ -11,21 +11,22 @@
     "direnv",
     "ECCS",
     "isready",
+    "lefthook",
+    "libquery",
     "lockb",
     "mytheme",
+    "nixpkgs",
+    "Noninteractive",
     "notistack",
+    "pkgs",
     "psql",
     "qiita",
     "reqwest",
+    "rustc",
     "safify",
-    "supabase",
-    "swiper",
-    "lefthook",
     "stdenv",
-    "rustc",
-    "pkgs",
-    "nixpkgs",
-    "libquery"
+    "supabase",
+    "swiper"
   ],
   "dictionaries": [
     "softwareTerms",
diff --git a/web/components/Header.tsx b/web/components/Header.tsx
index 60aaa9d7..40272047 100644
--- a/web/components/Header.tsx
+++ b/web/components/Header.tsx
@@ -33,7 +33,8 @@ export default function Header(props: Props) {
         </button>
         <div className="dropdown-content z-[1] w-56 rounded-box bg-base-100 p-2 shadow">
           <p className="p-2 text-xs">CourseMate は現在ベータ版です。</p>
-          <ul className="menu p-0">
+          {/* biome-ignore lint/a11y/noNoninteractiveTabindex: daisyUI の仕様。tabIndex を消すとモバイルで開かないなどの問題が起こる */}
+          <ul tabIndex={0} className="menu p-0">
             <li>
               <a
                 href="https://forms.gle/WvFTbsJoHjGp9Qt88"