diff --git a/lib/connectors/memory.js b/lib/connectors/memory.js
index a8b40e84..4d98e05e 100644
--- a/lib/connectors/memory.js
+++ b/lib/connectors/memory.js
@@ -347,18 +347,19 @@ Memory.prototype.all = function all(model, filter, callback) {
   });
 
   function sorting(a, b) {
+    var undefinedA, undefinedB;
+
     for (var i = 0, l = this.length; i < l; i++) {
+      undefinedB = b[this[i].key] === undefined && a[this[i].key] !== undefined;
+      undefinedA = a[this[i].key] === undefined && b[this[i].key] !== undefined;
 
-      if (a[this[i].key] === undefined && b[this[i].key] === undefined) {
-        return 0;
-      }
-
-      if (b[this[i].key] === undefined || a[this[i].key] > b[this[i].key]) {
+      if (undefinedB || a[this[i].key] > b[this[i].key]) {
         return 1 * this[i].reverse;
-      } else if (a[this[i].key] === undefined || a[this[i].key] < b[this[i].key]) {
+      } else if (undefinedA || a[this[i].key] < b[this[i].key]) {
         return -1 * this[i].reverse;
       }
     }
+
     return 0;
   }
 };