diff --git a/lib/ClassBuilder.js b/lib/ClassBuilder.js
index c5c0a4c..11bda6b 100644
--- a/lib/ClassBuilder.js
+++ b/lib/ClassBuilder.js
@@ -882,6 +882,8 @@ exports.prototype.createConcreteCtor = function( cname, members )
         // handle internal trait initialization logic, if provided
         if ( typeof this.___$$tctor$$ === 'function' )
         {
+            // FIXME: we're exposing _priv to something that can be
+            // malicously set by the user; encapsulate tctor
             this.___$$tctor$$.call( this, _priv );
         }