Different studies have observed that performance is a worse predictor of educational expectations among high-SES students. This result has been referred to as stickiness in high-SES students' expectations and explained as the outcome of the capacity and motivation of high-SES families to manage low performance so that it does not affect educational ambition and endanger social maintenance. However, little is known about how that stickiness is achieved. I use Spanish data from PISA 2018 to assess the role played by private schools in the stickiness of the expectation of enrolment in the academic track of upper secondary education. First, I report high stickiness in high-SES Spanish students' expectations. Then, I find that low performance is less detrimental to educational ambition in private schools, particularly for high-SES students. Finally, I simulate a counterfactual scenario where high-SES students enrol in private schools as often as low-SES students and observe that one-fifth of the stickiness in the expectation of academic-USE disappears.