diff --git a/common/js/types.d.ts b/common/js/types.d.ts
index c8051d959..fc14d2bf8 100644
--- a/common/js/types.d.ts
+++ b/common/js/types.d.ts
@@ -493,6 +493,7 @@ export interface MilestoneDocument extends MongoDBDocument {
     milestoneData: MilestoneSection[];
     milestoneID: string;
     group: string | null;
+    groupIndex: number | null;
 }
 export interface MilestoneGroupDocument extends MongoDBDocument {
     game: Game;
diff --git a/common/src/types.ts b/common/src/types.ts
index 5ed5d25df..4791a1d29 100644
--- a/common/src/types.ts
+++ b/common/src/types.ts
@@ -671,6 +671,7 @@ export interface MilestoneDocument extends MongoDBDocument {
     milestoneData: MilestoneSection[];
     milestoneID: string;
     group: string | null;
+    groupIndex: number | null;
 }
 
 export interface MilestoneGroupDocument extends MongoDBDocument {