Watergate Salad

1 (20 oz.) can crushed pineapple, undrained
1 (3 1/4 oz.) box instant pistachio pudding mix
1 lg. (12-13 oz.) Cool Whip
1 c. miniature marshmallows
1/2 c. chopped walnuts

Mix pineapple and dry pudding together. Then add Cool Whip, then after that, add nuts and marshmallows. Chill 3-4 hours. Serves 8.