diff --git a/backend/src/plugins/Tags/util/findTagByName.ts b/backend/src/plugins/Tags/util/findTagByName.ts
index 363006ff..1b877f33 100644
--- a/backend/src/plugins/Tags/util/findTagByName.ts
+++ b/backend/src/plugins/Tags/util/findTagByName.ts
@@ -14,9 +14,16 @@ export async function findTagByName(
   const categorySeparatorIndex = name.indexOf(".");
   if (categorySeparatorIndex > 0) {
     const categoryName = name.slice(0, categorySeparatorIndex);
-    const tagName = name.slice(categorySeparatorIndex + 1);
+    if (!Object.hasOwn(config.categories, categoryName)) {
+      return null;
+    }
+    const category = config.categories[categoryName];
 
-    return config.categories[categoryName]?.tags[tagName] ?? null;
+    const tagName = name.slice(categorySeparatorIndex + 1);
+    if (!Object.hasOwn(category.tags, tagName)) {
+      return null;
+    }
+    return category.tags[tagName];
   }
 
   // Dynamic tag