diff --git a/tools/deck/gen-slaydeck.mjs b/tools/deck/gen-slaydeck.mjs
index 8ee0fea..ca011f0 100644
--- a/tools/deck/gen-slaydeck.mjs
+++ b/tools/deck/gen-slaydeck.mjs
@@ -312,8 +312,8 @@ function entity({ id, path, modelId, entryId, componentNames, components, displa
 
 function upsertUi() {
   for (const g of ['combat', 'elite', 'boss']) {
-    if (!Array.isArray(SLOTS[g]) || SLOTS[g].length < 1) {
-      throw new Error(`[gen-slaydeck] monster-slots.json 의 "${g}" 그룹 좌표가 없습니다`);
+    if (!Array.isArray(SLOTS[g]) || SLOTS[g].length < MAX_MONSTERS) {
+      throw new Error(`[gen-slaydeck] monster-slots.json "${g}" 그룹 좌표(${SLOTS[g] ? SLOTS[g].length : 0}) < MAX_MONSTERS(${MAX_MONSTERS})`);
     }
   }
   const ui = JSON.parse(readFileSync(UI_FILE, 'utf8'));