MillerCoors has filed suit against Anheuser-Busch InBev over TV spots for Bud Light tweaking its rival for using “corn syrup” in its formulation, saying the ads are intentionally misleading.

The ads in question, which debuted during the Super Bowl, depict the “king” of Bud Light trundling a giant barrel labeled “corn syrup” up to the “castles” of Miller Lite and Coors Light and asking, “Is this your corn syrup?”

The lawsuit, filed in a federal court in Wisconsin, states that corn syrup is used as a “fermentation aid” in Miller Lite and Coors Light, as it is in some Anheuser-Busch products (though not Bud Light). It says that Bud Light is hoping consumers will confuse this ingredient with high-fructose corn syrup, a sweetener that has received bad publicity in recent years.

Anheuser-Busch maintains that the ads are “truthful” and does not plan to change the advertising.

In addition to the lawsuit, MillerCoors has fired back with its own ad, depicting a backstage scene at the Bud Light ad wher actors shed their knight costumes after shooting and crack open cans of Miller Lite.