diff --git a/lib/adapters/memory.js b/lib/adapters/memory.js
index ee840558..7982ad0f 100644
--- a/lib/adapters/memory.js
+++ b/lib/adapters/memory.js
@@ -245,7 +245,7 @@ Memory.prototype.updateAttributes = function updateAttributes(model, id, data, c
     var modelData = modelAsString && JSON.parse(modelAsString);
     
     if(modelData) {
-      this.save(model, merge(base, data), cb);
+      this.save(model, merge(modelData, data), cb);
     } else {
       cb(new Error('Could not update attributes. Object with id ' + id + ' does not exist!'));
     }