--- a/playground/jsonld.js Mon Apr 16 15:03:06 2012 -0400 +++ b/playground/jsonld.js Mon Apr 16 16:15:05 2012 -0400 @@ -763,7 +763,7 @@ } // return null for invalid key - if(!key) { + if(key === null) { rval = null; } // return entire context entry if type is unspecified