diff --git a/app/tags.js b/app/tags.js
index 112e3d5..4668611 100644
--- a/app/tags.js
+++ b/app/tags.js
@@ -18,10 +18,12 @@ export function categorizeTags(tags, releaseTagNames) {
   const keep = new Set(releaseTagNames)
 
   return tags.map((tag) => {
-    if (isEmptyOrNull(tag.name)) {
+    // 防禦 null/非物件 tag 與非字串 name:一律歸為 skip,避免後續存取或比對時出錯。
+    const name = tag?.name
+    if (typeof name !== 'string' || isEmptyOrNull(name)) {
       return { tag, action: 'skip' }
     }
-    if (keep.has(tag.name)) {
+    if (keep.has(name)) {
       return { tag, action: 'keep' }
     }
     return { tag, action: 'delete' }