diff --git a/lib/her/model.rb b/lib/her/model.rb
index <HASH>..<HASH> 100644
--- a/lib/her/model.rb
+++ b/lib/her/model.rb
@@ -40,6 +40,7 @@ module Her
     # Supported ActiveModel modules
     include ActiveModel::AttributeMethods
     include ActiveModel::Validations
+    include ActiveModel::Validations::Callbacks
     include ActiveModel::Conversion
     include ActiveModel::Dirty
     include ActiveModel::Naming
Adding Active model before and after validation

We have method valid? which is requested from ActiveModel
and don't have any callback to update values before it