diff --git a/lib/immortal.rb b/lib/immortal.rb
index 109ada2..723fb67 100644
--- a/lib/immortal.rb
+++ b/lib/immortal.rb
@@ -84,7 +84,7 @@ def find_only_deleted(*args)
     end
 
     def immortal_delete_all(conditions = nil)
-      unscoped.update_all({:deleted => 1}, conditions)
+      unscoped.update_all({:deleted => true}, conditions)
     end
 
     def delete_all!(*args)