diff --git a/api/prisma/schema.prisma b/api/prisma/schema.prisma
index c93da9b1fff..f9f055d6480 100644
--- a/api/prisma/schema.prisma
+++ b/api/prisma/schema.prisma
@@ -208,6 +208,7 @@ model MsUsername {
   msUsername String
 
   @@index([userId, id], map: "userId_1__id_1")
+  @@index([msUsername], map: "msUsername_1")
 }
 
 model Exam {