diff --git a/iron-validatable-behavior.html b/iron-validatable-behavior.html
index c59c47e..a264668 100644
--- a/iron-validatable-behavior.html
+++ b/iron-validatable-behavior.html
@@ -91,7 +91,11 @@
      * @return {boolean} True if `values` is valid.
      */
     validate: function(values) {
-      var valid = this._validator && this._validator.validate(values);
+      var valid = true;
+      if (this.hasValidator()) {
+        valid = this._validator.validate(values);
+      }
+
       this.invalid = !valid;
       return valid;
     }
diff --git a/test/iron-validatable-behavior.html b/test/iron-validatable-behavior.html
index 435c034..847a3f8 100644
--- a/test/iron-validatable-behavior.html
+++ b/test/iron-validatable-behavior.html
@@ -45,6 +45,12 @@
         assert.isFalse(node.hasAttribute('aria-invalid'), 'aria-invalid is unset');
       });
 
+      test('validate() is true if a validator isn\'t set', function() {
+        var node = fixture('basic');
+        var valid = node.validate();
+        assert.isTrue(valid);
+      });
+
     });
 
   </script>