diff --git a/lib/paperclip/matchers/validate_attachment_content_type_matcher.rb b/lib/paperclip/matchers/validate_attachment_content_type_matcher.rb
index 1dcf3678f..fec6f0457 100644
--- a/lib/paperclip/matchers/validate_attachment_content_type_matcher.rb
+++ b/lib/paperclip/matchers/validate_attachment_content_type_matcher.rb
@@ -33,7 +33,7 @@ def rejecting *types
 
         def matches? subject
           @subject = subject
-          @subject = @subject.class unless Class === @subject
+          @subject = @subject.new if @subject.class == Class
           @allowed_types && @rejected_types &&
           allowed_types_allowed? && rejected_types_rejected?
         end
@@ -63,9 +63,9 @@ def description
         def type_allowed?(type)
           file = StringIO.new(".")
           file.content_type = type
-          (subject = @subject.new).attachment_for(@attachment_name).assign(file)
-          subject.valid?
-          subject.errors[:"#{@attachment_name}_content_type"].blank?
+          @subject.attachment_for(@attachment_name).assign(file)
+          @subject.valid?
+          @subject.errors[:"#{@attachment_name}_content_type"].blank?
         end
 
         def allowed_types_allowed?
diff --git a/lib/paperclip/matchers/validate_attachment_presence_matcher.rb b/lib/paperclip/matchers/validate_attachment_presence_matcher.rb
index 37c4db061..6f732a02d 100644
--- a/lib/paperclip/matchers/validate_attachment_presence_matcher.rb
+++ b/lib/paperclip/matchers/validate_attachment_presence_matcher.rb
@@ -18,7 +18,7 @@ def initialize attachment_name
 
         def matches? subject
           @subject = subject
-          @subject = @subject.class unless Class === @subject
+          @subject = subject.new if subject.class == Class
           error_when_not_valid? && no_error_when_valid?
         end
 
@@ -37,16 +37,16 @@ def description
         protected
 
         def error_when_not_valid?
-          (subject = @subject.new).send(@attachment_name).assign(nil)
-          subject.valid?
-          not subject.errors[:"#{@attachment_name}_file_name"].blank?
+          @subject.send(@attachment_name).assign(nil)
+          @subject.valid?
+          not @subject.errors[:"#{@attachment_name}_file_name"].blank?
         end
 
         def no_error_when_valid?
           @file = StringIO.new(".")
-          (subject = @subject.new).send(@attachment_name).assign(@file)
-          subject.valid?
-          subject.errors[:"#{@attachment_name}_file_name"].blank?
+          @subject.send(@attachment_name).assign(@file)
+          @subject.valid?
+          @subject.errors[:"#{@attachment_name}_file_name"].blank?
         end
       end
     end
diff --git a/lib/paperclip/matchers/validate_attachment_size_matcher.rb b/lib/paperclip/matchers/validate_attachment_size_matcher.rb
index 62bd67b81..b821af44b 100644
--- a/lib/paperclip/matchers/validate_attachment_size_matcher.rb
+++ b/lib/paperclip/matchers/validate_attachment_size_matcher.rb
@@ -38,7 +38,7 @@ def in range
 
         def matches? subject
           @subject = subject
-          @subject = @subject.class unless Class === @subject
+          @subject = @subject.new if @subject.class == Class
           lower_than_low? && higher_than_low? && lower_than_high? && higher_than_high?
         end
 
@@ -67,9 +67,9 @@ def passes_validation_with_size(new_size)
           override_method(file, :size){ new_size }
           override_method(file, :to_tempfile){ file }
 
-          (subject = @subject.new).send(@attachment_name).assign(file)
-          subject.valid?
-          subject.errors[:"#{@attachment_name}_file_size"].blank?
+          @subject.send(@attachment_name).assign(file)
+          @subject.valid?
+          @subject.errors[:"#{@attachment_name}_file_size"].blank?
         end
 
         def lower_than_low?
diff --git a/test/matchers/validate_attachment_content_type_matcher_test.rb b/test/matchers/validate_attachment_content_type_matcher_test.rb
index 551f490e2..35d9a1520 100644
--- a/test/matchers/validate_attachment_content_type_matcher_test.rb
+++ b/test/matchers/validate_attachment_content_type_matcher_test.rb
@@ -83,5 +83,28 @@ class ValidateAttachmentContentTypeMatcherTest < Test::Unit::TestCase
 
       should_reject_dummy_class
     end
+
+    context "using an :if to control the validation" do
+      setup do
+        @dummy_class.class_eval do
+          validates_attachment_content_type :avatar, :content_type => %r{image/*} , :if => :go
+          attr_accessor :go
+        end
+        @matcher = self.class.validate_attachment_content_type(:avatar).
+                        allowing(%w(image/png image/jpeg)).
+                        rejecting(%w(audio/mp3 application/octet-stream))
+        @dummy = @dummy_class.new
+      end
+
+      should "run the validation if the control is true" do
+        @dummy.go = true
+        assert_accepts @matcher, @dummy
+      end
+
+      should "not run the validation if the control is false" do
+        @dummy.go = false
+        assert_rejects @matcher, @dummy
+      end
+    end
   end
 end
diff --git a/test/matchers/validate_attachment_presence_matcher_test.rb b/test/matchers/validate_attachment_presence_matcher_test.rb
index e798aaf00..341e4f883 100644
--- a/test/matchers/validate_attachment_presence_matcher_test.rb
+++ b/test/matchers/validate_attachment_presence_matcher_test.rb
@@ -22,5 +22,26 @@ class ValidateAttachmentPresenceMatcherTest < Test::Unit::TestCase
 
       should_accept_dummy_class
     end
+
+    context "using an :if to control the validation" do
+      setup do
+        @dummy_class.class_eval do
+          validates_attachment_presence :avatar, :if => :go
+          attr_accessor :go
+        end
+        @dummy = @dummy_class.new
+        @dummy.avatar = nil
+      end
+
+      should "run the validation if the control is true" do
+        @dummy.go = true
+        assert_accepts @matcher, @dummy
+      end
+
+      should "not run the validation if the control is false" do
+        @dummy.go = false
+        assert_rejects @matcher, @dummy
+      end
+    end
   end
 end
diff --git a/test/matchers/validate_attachment_size_matcher_test.rb b/test/matchers/validate_attachment_size_matcher_test.rb
index 0434a7c01..0285ce348 100644
--- a/test/matchers/validate_attachment_size_matcher_test.rb
+++ b/test/matchers/validate_attachment_size_matcher_test.rb
@@ -47,5 +47,26 @@ class ValidateAttachmentSizeMatcherTest < Test::Unit::TestCase
         should_accept_dummy_class
       end
     end
+
+    context "using an :if to control the validation" do
+      setup do
+        @dummy_class.class_eval do
+          validates_attachment_size :avatar, :greater_than => 1024, :if => :go
+          attr_accessor :go
+        end
+        @dummy = @dummy_class.new
+        @matcher = self.class.validate_attachment_size(:avatar).greater_than(1024)
+      end
+
+      should "run the validation if the control is true" do
+        @dummy.go = true
+        assert_accepts @matcher, @dummy
+      end
+
+      should "not run the validation if the control is false" do
+        @dummy.go = false
+        assert_rejects @matcher, @dummy
+      end
+    end
   end
 end