diff --git a/backbone.js b/backbone.js
index 610cdad1..e57932af 100644
--- a/backbone.js
+++ b/backbone.js
@@ -699,7 +699,7 @@
 
     // Check if the model is currently in a valid state.
     isValid: function(options) {
-      return this._validate({}, _.extend(options || {}, { validate: true }));
+      return this._validate({}, _.defaults({validate: true}, options));
     },
 
     // Run validation against the next complete set of model attributes,