diff --git a/lib/client/types/form/story.ts b/lib/client/types/form/story.ts
index 81c24b5..fa45acd 100644
--- a/lib/client/types/form/story.ts
+++ b/lib/client/types/form/story.ts
@@ -20,6 +20,7 @@ export interface FormChapter {
 
 export interface FormStory {
 	title: string;
+	coAuthor: number | null;
 	chapters: FormChapter[];
 	ficmas?: number | null;
 	challenge?: number | null;
@@ -44,6 +45,7 @@ export const defaultChapter: FormChapter = {
 
 export const defaultStory: FormStory = {
 	title: "",
+	coAuthor: null,
 	chapters: [],
 	ficmas: null,
 	challenge: null,