Is the KJV wording holy ‘thing’ wrong in Luke 1:35?

Luke states the following in 1:35 : και το γεννωμενον αγιον κληθησεται υιος θεου also that holy thing which shall be born of thee shall be called the Son of God [KJV] Note : My question relates to the TR text (I am quoting Stephens 1550)…