diff --git a/src/pages/api/exam/[module]/index.ts b/src/pages/api/exam/[module]/index.ts
index af9a7783..86e2e7d6 100644
--- a/src/pages/api/exam/[module]/index.ts
+++ b/src/pages/api/exam/[module]/index.ts
@@ -62,18 +62,13 @@ async function POST(req: NextApiRequest, res: NextApiResponse) {
 
 			// Check whether the id of the exam matches another exam with different
 			// owners, throw exception if there is, else allow editing
-			const ownersSet = new Set(docSnap?.owners || []);
+			const existingExamOwners = docSnap?.owners ?? [];
+			const newExamOwners = exam.owners ?? [];
 
-			if (docSnap !== null) {
-				if (docSnap.owners === undefined) {
-					docSnap.owners = [];
-				}
-				if (exam.owners === undefined) {
-					exam.owners = [];
-				}
-				if (docSnap.owners?.length !== exam.owners?.length || !exam.owners?.every((e: string) => ownersSet.has(e))) {
-					throw new Error("Name already exists");
-				}
+			const ownersSet = new Set(existingExamOwners);
+
+			if (docSnap !== null && (existingExamOwners.length !== newExamOwners.length || !newExamOwners.every((e: string) => ownersSet.has(e)))) {
+				throw new Error("Name already exists");
 			}
 
 			await db.collection(module).updateOne(