diff --git a/lib/compass/sass_extensions/sprites/engines.rb b/lib/compass/sass_extensions/sprites/engines.rb
index 26a73260..1a3daee3 100644
--- a/lib/compass/sass_extensions/sprites/engines.rb
+++ b/lib/compass/sass_extensions/sprites/engines.rb
@@ -1 +1,24 @@
+module Compass
+  module SassExtensions
+    module Sprites
+      class Engine
+        attr_accessor :width, :height, :images
+        def initialize(width, height, images)
+          @width, @height, @images = width, height, images
+        end
+        
+        def construct_sprite
+          raise ::Compass::Error, "You must impliment construct_sprite"
+        end
+        
+        def save(filename)
+          raise ::Compass::Error, "You must impliment save(filename)"
+        end
+        
+      end
+    end
+  end
+end
+
+
 require 'compass/sass_extensions/sprites/engines/chunky_png_engine'
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