diff --git a/anne-survey.rb b/anne-survey.rb
index 11173d5..6996778 100644
--- a/anne-survey.rb
+++ b/anne-survey.rb
@@ -7,8 +7,10 @@ Markaby::Builder.set(:indent, 2)
 
 Camping.goes :Anne
 
-PUBLIC_DIR = Pathname.new(__FILE__).dirname + "public"
-IMAGE_DIR = PUBLIC_DIR + "images"
+unless defined? PUBLIC_DIR
+  PUBLIC_DIR = Pathname.new(__FILE__).dirname + "public"
+  IMAGE_DIR = PUBLIC_DIR + "images"
+end
 
 module Anne