diff --git a/migration/src/migrate/repository.ts b/migration/src/migrate/repository.ts
index 8d9167a31..139a2fb50 100644
--- a/migration/src/migrate/repository.ts
+++ b/migration/src/migrate/repository.ts
@@ -47,12 +47,7 @@ export default class MigrationRepository {
   }
 
   async insertCourses(courses: CourseEntity[]): Promise<void> {
-    await this.manager
-      .createQueryBuilder()
-      .insert()
-      .into("courses")
-      .values(courses)
-      .execute();
+    await this.manager.save(courses, { chunk: 1000 });
   }
 
   async updateUser(zid: string) {
diff --git a/migration/src/migrate/service.ts b/migration/src/migrate/service.ts
index 3ed0a68bb..4415e5d67 100644
--- a/migration/src/migrate/service.ts
+++ b/migration/src/migrate/service.ts
@@ -216,7 +216,7 @@ export default class MigrationService {
           console.log("Unknown term: ", term);
         }
       }
-      return termNums;
+      return termNums.filter((term) => !isNaN(term));
     };
 
     const entity = new CourseEntity();