In the Hittite phonological system there was a labialized velar fricative /xw/ beside the plain velar fricative /x/ parallel to the opposition between the velar stops /kw/ and /k/. The frequent syllable /xwa/ was spelled either hu-(u) or hu-wa. Evidence from the frequency of words with initial hu in the lexicon, from spelling variations and from ablaut alternations is presented to demonstrate the existence of /xw/. It is suggested that Hittite /xw/ regularly corresponds to the reflexes of *w in the non-Anatolian Indo-European languages.