diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 36819553ee..843c0c3cb5 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -63,7 +63,7 @@ module ActiveModel
   class Errors
     include Enumerable
 
-    CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank]
+    CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
 
     attr_reader :messages
 
@@ -218,6 +218,9 @@ module ActiveModel
       elsif message.is_a?(Proc)
         message = message.call
       end
+      if options[:strict]
+        raise ActiveModel::StrictValidationFailed,  message
+      end
 
       self[attribute] << message
     end
@@ -319,4 +322,7 @@ module ActiveModel
       I18n.translate(key, options)
     end
   end
+
+  class StrictValidationFailed < StandardError
+  end
 end
diff --git a/activemodel/lib/active_model/validations/acceptance.rb b/activemodel/lib/active_model/validations/acceptance.rb
index 01907ac9da..e628c6f306 100644
--- a/activemodel/lib/active_model/validations/acceptance.rb
+++ b/activemodel/lib/active_model/validations/acceptance.rb
@@ -58,6 +58,8 @@ module ActiveModel
       #   <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).
       #   The method, proc or string should return or evaluate to a true or
       #   false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_acceptance_of(*attr_names)
         validates_with AcceptanceValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index a9dcb0b505..6573a7d264 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -58,6 +58,8 @@ module ActiveModel
       #   <tt>:unless => :skip_validation</tt>, or
       #   <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_confirmation_of(*attr_names)
         validates_with ConfirmationValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/exclusion.rb b/activemodel/lib/active_model/validations/exclusion.rb
index d3b8d31502..644cc814a7 100644
--- a/activemodel/lib/active_model/validations/exclusion.rb
+++ b/activemodel/lib/active_model/validations/exclusion.rb
@@ -59,6 +59,8 @@ module ActiveModel
       # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_exclusion_of(*attr_names)
         validates_with ExclusionValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/format.rb b/activemodel/lib/active_model/validations/format.rb
index 090e8cfbae..d3faa8c6a6 100644
--- a/activemodel/lib/active_model/validations/format.rb
+++ b/activemodel/lib/active_model/validations/format.rb
@@ -84,6 +84,8 @@ module ActiveModel
       # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_format_of(*attr_names)
         validates_with FormatValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/inclusion.rb b/activemodel/lib/active_model/validations/inclusion.rb
index 9a9270d615..147e2ecb69 100644
--- a/activemodel/lib/active_model/validations/inclusion.rb
+++ b/activemodel/lib/active_model/validations/inclusion.rb
@@ -59,6 +59,8 @@ module ActiveModel
       # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_inclusion_of(*attr_names)
         validates_with InclusionValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index 144e73904e..eb7aac709d 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -96,6 +96,8 @@ module ActiveModel
       # * <tt>:tokenizer</tt> - Specifies how to split up the attribute string. (e.g. <tt>:tokenizer => lambda {|str| str.scan(/\w+/)}</tt> to
       #   count words as in above example.)
       #   Defaults to <tt>lambda{ |value| value.split(//) }</tt> which counts individual characters.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       def validates_length_of(*attr_names)
         validates_with LengthValidator, _merge_attributes(attr_names)
       end
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 0d1903362c..34d447a0fa 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -107,6 +107,8 @@ module ActiveModel
       # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
       #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       #
       # The following checks can also be supplied with a proc or a symbol which corresponds to a method:
       # * <tt>:greater_than</tt>
diff --git a/activemodel/lib/active_model/validations/presence.rb b/activemodel/lib/active_model/validations/presence.rb
index cfb4c33dcc..35af7152db 100644
--- a/activemodel/lib/active_model/validations/presence.rb
+++ b/activemodel/lib/active_model/validations/presence.rb
@@ -35,6 +35,8 @@ module ActiveModel
       # * <tt>unless</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).
       #   The method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
       #
       def validates_presence_of(*attr_names)
         validates_with PresenceValidator, _merge_attributes(attr_names)
diff --git a/activemodel/lib/active_model/validations/validates.rb b/activemodel/lib/active_model/validations/validates.rb
index 7ff42de00b..43b095d11a 100644
--- a/activemodel/lib/active_model/validations/validates.rb
+++ b/activemodel/lib/active_model/validations/validates.rb
@@ -70,8 +70,8 @@ module ActiveModel
       # validator's initializer as +options[:in]+ while other types including
       # regular expressions and strings are passed as +options[:with]+
       #
-      # Finally, the options +:if+, +:unless+, +:on+, +:allow_blank+ and +:allow_nil+ can be given
-      # to one specific validator, as a hash:
+      # Finally, the options +:if+, +:unless+, +:on+, +:allow_blank+, +:allow_nil+ and +:strict+ 
+      # can be given to one specific validator, as a hash:
       #
       #   validates :password, :presence => { :if => :password_required? }, :confirmation => true
       #
@@ -101,12 +101,24 @@ module ActiveModel
         end
       end
 
+      # This method is used to define validation that can not be correcterized by end user 
+      # and is considered exceptional. 
+      # So each validator defined with bang or <tt>:strict</tt> option set to <tt>true</tt>
+      # will always raise <tt>ActiveModel::InternalValidationFailed</tt> instead of adding error
+      # when validation fails
+      # See <tt>validates</tt> for more information about validation itself.
+      def validates!(*attributes)
+        options = attributes.extract_options!
+        options[:strict] = true
+        validates(*(attributes << options))
+      end
+
     protected
 
       # When creating custom validators, it might be useful to be able to specify
       # additional default keys. This can be done by overwriting this method.
       def _validates_default_keys
-        [ :if, :unless, :on, :allow_blank, :allow_nil ]
+        [ :if, :unless, :on, :allow_blank, :allow_nil , :strict]
       end
 
       def _parse_validates_options(options) #:nodoc:
diff --git a/activemodel/lib/active_model/validations/with.rb b/activemodel/lib/active_model/validations/with.rb
index a87b213fe4..83aae206a6 100644
--- a/activemodel/lib/active_model/validations/with.rb
+++ b/activemodel/lib/active_model/validations/with.rb
@@ -61,7 +61,9 @@ module ActiveModel
       #   (e.g. <tt>:unless => :skip_validation</tt>, or
       #   <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).
       #   The method, proc or string should return or evaluate to a true or false value.
-      #
+      # * <tt>:strict</tt> - Specifies whether validation should be strict. 
+      #   See <tt>ActiveModel::Validation#validates!</tt> for more information
+
       # If you pass any additional configuration options, they will be passed
       # to the class and available as <tt>options</tt>:
       #
@@ -140,4 +142,4 @@ module ActiveModel
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index 0b50acf913..2f4376bd41 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -297,4 +297,37 @@ class ValidationsTest < ActiveModel::TestCase
 
     assert auto.valid?
   end
+
+  def test_strict_validation_in_validates
+    Topic.validates :title, :strict => true, :presence => true
+    assert_raises ActiveModel::StrictValidationFailed do
+      Topic.new.valid?
+    end
+  end
+
+  def test_strict_validation_not_fails
+    Topic.validates :title, :strict => true, :presence => true
+    assert Topic.new(:title => "hello").valid?
+  end
+
+  def test_strict_validation_particular_validator
+    Topic.validates :title,  :presence => {:strict => true}
+    assert_raises ActiveModel::StrictValidationFailed do
+      Topic.new.valid?
+    end
+  end
+
+  def test_strict_validation_in_custom_validator_helper
+    Topic.validates_presence_of :title, :strict => true
+    assert_raises ActiveModel::StrictValidationFailed do
+      Topic.new.valid?
+    end
+  end
+
+  def test_validates_with_bang
+    Topic.validates! :title,  :presence => true
+    assert_raises ActiveModel::StrictValidationFailed do
+      Topic.new.valid?
+    end
+  end
 end