The 'Turn My Swag On' rapper took to the micro-blogging site to make the claim that he is responsible for the lyrics in the 10-year-old's recent hit track.
He wrote: "YES ITS TRUE I WROTE "WHIP MY HAIR" FOR WILLOW SMITH. THATS WHY SHE SAYS HOP OUT THE BED TURN MY SWAG ON. WE GETTING $$$ 2011 NO GAMES (sic)"
WENN reports that the songwriting team credited with creating Smith's single is Ronald Jackson and Janae Rockwell - but that Soulja Boy is rumoured to have trademarked the phrase "turn my swag on", which could result in royalties being owed to the rapper.
Smith's representatives have yet to comment on the claims.