How to fix Can't create table `nuevosem_laravel`.`assignatures` (errno: 150 "Foreign key constraint is incorrectly formed")

I'm trying to migrate some files, but when I try to migrate the "Subject" migrate file, the artisan outputs:

Illuminate\Database\QueryException : SQLSTATE[HY000]: General error: 1005 Can't create table nuevosem_laravel.subjects (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table subjects add constraint subjects_teacher_foreign foreign key (teacher) references teachers (name))

I'm running Laravel on Xampp 3.2.4

The "teachers" Schema:

  Schema::create('teachers', function (Blueprint $table) {
      $table->increments('id')->unsigned();
      $table->string('name');
      $table->string('code')->unique();
      $table->timestamps();
  });

The "subject" Schema:

Schema::create('subjects', function (Blueprint $table) {

      $table->string('period');
      $table->string('teacher');
      $table->foreign('teacher')->references('name')->on('teachers');
      $table->integer('nrc')->unsingned();
      $table->string('key');
      $table->string('section');
      $table->enum('type', ['TEO', 'LAB']);
      $table->string('schedule');
      $table->string('days');
      $table->string('classroom');
      $table->string('subject');
      $table->timestamps();
  });

via Chebli Mohamed