diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 04b67cdf3a8db4d9c2edd27bfeb36ac7f4857165..344ee6416df00e212e89725ce5ae4d456e905762 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Allow before and after validations to take an array of lifecycle events
+
+    *John Foley*
+
 *   Support for specifying transaction isolation level
 
     If your database supports setting the isolation level for a transaction, you can set
diff --git a/guides/source/active_record_validations_callbacks.md b/guides/source/active_record_validations_callbacks.md
index e5957d8acba46e0597aed4ff55696672eadace4b..f32c1050ce06bb2cd4e88a7b9a32d26014d465c2 100644
--- a/guides/source/active_record_validations_callbacks.md
+++ b/guides/source/active_record_validations_callbacks.md
@@ -995,6 +995,25 @@ class User < ActiveRecord::Base
 end
 ```
 
+Callbacks can also be registered to only fire on certain lifecycle events:
+<ruby>
+class User < ActiveRecord::Base
+  before_validation :normalize_name, :on => :create
+  
+  # :on takes an array as well
+  after_validation :set_location, :on => [ :create, :update ]
+
+  protected
+  def normalize_name
+    self.name = self.name.downcase.titleize
+  end
+
+  def set_location
+    self.location = LocationService.query(self)
+  end
+end
+</ruby>
+
 It is considered good practice to declare callback methods as protected or private. If left public, they can be called from outside of the model and violate the principle of object encapsulation.
 
 Available Callbacks