Garlic Lime Chicken

4 boneless, skinless chicken breasts
1/2 cup soy sauce
1/4 cup fresh lime juice
1 Tbs. Worcestershire sauce
2 garlic cloves, minced
1/2 tsp. dry mustard
1/2 tsp. coarsely ground pepper

Place chicken in bottom of slow cooker. Mix together remaining ingredients and pour over top of chicken. Cover and cook on low for 6 to 8 hours.