diff --git a/lib/seed-fu.rb b/lib/seed-fu.rb
index 248d54d..3abb0e1 100644
--- a/lib/seed-fu.rb
+++ b/lib/seed-fu.rb
@@ -75,7 +75,8 @@ def self.seed(*constraints, &block)
   end
   
   def self.seed_once(*constraints, &block)
-    SeedFu::Seeder.plant(self, *constraints, true, &block)
+    constraints << true
+    SeedFu::Seeder.plant(self, *constraints, &block)
   end
 
   def self.seed_many(*constraints)