diff --git a/D03_PlanAnalysis/D03_PlanAnalysis_Api.ts b/D03_PlanAnalysis/D03_PlanAnalysis_Api.ts
index d0219ef8a..d655ce616 100644
--- a/D03_PlanAnalysis/D03_PlanAnalysis_Api.ts
+++ b/D03_PlanAnalysis/D03_PlanAnalysis_Api.ts
@@ -98,7 +98,7 @@ export interface PlanNetworkView {
   network: ServerNetwork | null;
   derived: {
     lines: Array<{ id: string; length_m: number; stations: number[] }>;
-    pieces: Array<PlanPiece & { length_m: number; planned: Vertex[] }>;
+    pieces: Array<PlanPiece & { set_key: string; length_m: number; planned: Vertex[] }>;
     /** 세트(638) — 열쇠 「연도-번호」 · 덩이 수(`parts` > 1 = 끊김) · 세트 안 갈래 · 조각 id. */
     sets: PlanSetView[];
   } | null;