With extended viewing, a triangle-wave grating takes on an unstable, illusory appearance, such that at times it more nearly resembles a square-wave grating. Prior adaptation to a genuine square-wave grating temporarily reduces the incidence of this illusory percept, stabilizing the appearance of a triangle-wave grating. The present experiment measured the effect of adapting to a square-wave grating that was suppressed during binocular rivalry for a substantial portion of the adaptation period. Rivalry suppression reduced the effectiveness of the adaptation pattern, indicating that the neural site of adaptation follows the locus of suppression.