diff --git a/test/collections.js b/test/collections.js
index 4bce6668e..4036d1fd2 100644
--- a/test/collections.js
+++ b/test/collections.js
@@ -496,6 +496,33 @@
 
     list = ['q', 'w', 'e', 'r', 't', 'y'];
     deepEqual(_.sortBy(list), ['e', 'q', 'r', 't', 'w', 'y'], 'uses _.identity if iterator is not specified');
+
+    var smallCollection = _.shuffle(_.map(collection.slice(2, 7), function(pair) {
+      return {x: pair.x, y: pair.y};
+    }));
+    sorted = [{x: 1, y: 3}, {x: 1, y: 4}, {x: 1, y: 5}, {x: 1, y: 6}, {x: 2, y: 1}];
+
+    deepEqual(_.sortBy(smallCollection, function(pair) {
+      return [pair.x, pair.y];
+    }), sorted, 'Returning an array will sort by precedence');
+
+    deepEqual(_.sortBy(smallCollection, function(pair) {
+      return [pair.y, pair.x];
+    }), _.sortBy(smallCollection, 'y'));
+
+    smallCollection = _.shuffle([{a: 1, b: 2}, {a: 1}, {a: 1, b: 3}, {a: 2, b: -1}, {b: 5}]);
+
+    deepEqual(_.sortBy([{a: 2}, {a: 2, b: 2}, {a: 2, b: undefined}], function(x) {
+      return 'b' in x ? [x.a, x.b] : [x.a];
+    }), [{a: 2}, {a: 2, b: 2}, {a: 2, b: undefined}], 'array of longer length more important');
+
+    deepEqual(_.sortBy([{a: 2}, {a: 1, b: 2}], function(x) {
+      return 'b' in x ? [x.a, x.b] : [x.a];
+    }), [{a: 1, b: 2}, {a: 2}], 'precedence more important than length');
+
+    deepEqual(_.sortBy(smallCollection, function(x) {
+      return [x.a, x.b];
+    }), [{a: 1, b: 2}, {a: 1, b: 3}, {a: 1}, {a: 2, b: -1}, {b: 5}]);
   });
 
   test('groupBy', function() {
diff --git a/underscore.js b/underscore.js
index 130b917aa..f2bfa7782 100644
--- a/underscore.js
+++ b/underscore.js
@@ -358,13 +358,19 @@
         criteria: iterator(value, index, list)
       };
     }).sort(function(left, right) {
-      var a = left.criteria;
-      var b = right.criteria;
-      if (a !== b) {
-        if (a > b || a === void 0) return 1;
-        if (a < b || b === void 0) return -1;
+      var leftArr = left.criteria;
+      var rightArr = right.criteria;
+      leftArr = _.isArray(leftArr) ? leftArr : [leftArr];
+      rightArr = _.isArray(rightArr) ? rightArr : [rightArr];
+      for (var i = 0, len = leftArr.length, blen = rightArr.length; i < len; i++) {
+        if (i >= blen) return 1;
+        var a = leftArr[i], b = rightArr[i];
+        if (a !== b) {
+          if (a > b || a === void 0) return 1;
+          if (a < b || b === void 0) return -1;
+        }
       }
-      return left.index - right.index;
+      return blen == len ? left.index - right.index : -1;
     }), 'value');
   };