Bug fix: #3266

lib/associations/mixin.js

@@ -347,8 +347,9 @@ Mixin.belongsToMany = function(targetModel, options) {
   options = options || {};
   options.hooks = options.hooks === undefined ? false : Boolean(options.hooks);
   options.useHooks = options.hooks;
+  options.timestamps = options.timestamps === undefined ? this.sequelize.options.timestamps : options.timestamps;
   
-  options = Utils._.extend(options, Utils._.omit(sourceModel.options, ['hooks']));
+  options = Utils._.extend(options, Utils._.omit(sourceModel.options, ['hooks', 'timestamps']));
 
   // the id is in the foreign table or in a connecting table
   var association = new BelongsToMany(sourceModel, targetModel, options);