diff --git a/app/helpers/boxes_helper.rb b/app/helpers/boxes_helper.rb
index f7d4c48..dbec31d 100644
--- a/app/helpers/boxes_helper.rb
+++ b/app/helpers/boxes_helper.rb
@@ -61,6 +61,8 @@ module BoxesHelper
       end
     when Proc
       self.instance_eval(&content)
+    when NilClass
+      ''
     else
       raise "Unsupported content for block (#{content.class})"
     end
diff --git a/app/models/block.rb b/app/models/block.rb
index 334005b..3c48963 100644
--- a/app/models/block.rb
+++ b/app/models/block.rb
@@ -25,11 +25,21 @@ class Block < ActiveRecord::Base
   # * <tt>Proc</tt>: the Proc is evaluated in the scope of BoxesHelper. The
   # block can then use <tt>render</tt>, <tt>link_to</tt>, etc.
   #
+  # The method can also return <tt>nil</tt>, which means "no footer".
+  #
   # See BoxesHelper#extract_block_content for implementation details. 
   def content
     "This is block number %d" % self.id
   end
 
+  # A footer to be appended to the end of the block. Returns <tt>nil</tt>.
+  #
+  # Override in your subclasses. You can return the same types supported by
+  # #content.
+  def footer
+    nil
+  end
+
   # must return a Hash with URL options poiting to the action that edits
   # properties of the block
   def editor
@@ -49,12 +59,4 @@ class Block < ActiveRecord::Base
     self.class.name.underscore.gsub('_', '-')
   end
 
-  # A footer to be appended to the end of the block. Returns an empty string.
-  #
-  # Override in your subclasses. You can return the same types supported by
-  # #content.
-  def footer
-    ''
-  end
-
 end
diff --git a/test/unit/block_test.rb b/test/unit/block_test.rb
index 5b4905f..46d977b 100644
--- a/test/unit/block_test.rb
+++ b/test/unit/block_test.rb
@@ -28,8 +28,8 @@ class BlockTest < Test::Unit::TestCase
     assert_equal 'something-block', block.css_class_name
   end
 
-  should 'provide an empty footer by default' do
-    assert_equal '', Block.new.footer
+  should 'provide no footer by default' do
+    assert_nil Block.new.footer
   end
 
 end
--
libgit2 0.21.2