Use :validation callbacks, not the :validate callbacks reserved by ActiveModel, ensuring callbacks are actually run when they're supposed to be.

lib/couchrest/model/callbacks.rb

@@ -12,8 +12,7 @@ module CouchRest #:nodoc:
           :create,
           :destroy,
           :save,
-          :update,
-          :validate
+          :update
 
       end
 

lib/couchrest/model/validations.rb

@@ -15,6 +15,7 @@ module CouchRest
       extend ActiveSupport::Concern
       included do
         include ActiveModel::Validations
+        include ActiveModel::Validations::Callbacks
       end