We build on previous theories of junior minister allocation and coalition oversight by incorporating a novel theory of strategic changes in the issues covered in party manifestos. We argue that parties use junior ministerial appointments to oversee their coalition partners on portfolios that correspond to issues emphasized by the parties’ activists when the coalition partner’s preferences deviate from the party’s. The findings, based on a data set of more than 2800 party-portfolio dyads in 10 countries, show significant support for these expectations. We find that party leaders who successfully negotiate for junior ministers to particular portfolios are most concerned about checking ideologically contentious coalition partners in areas of concern to activists. The results also illustrate the usefulness of our dyadic approach for the study of junior minister allocation.