In Zhong (Philos Phenomenol Res 83:129–147, 2011; Analysis 72:75–85, 2012), I argued that, contrary to what many people might expect, the counterfactual theory of causation will generate (rather than solve) the exclusion problem. Recently some philosophers raise an incisive objection to this argument. They contend that my argument fails as it equivocates between different notions of a physical realizer (see Christensen and Kallestrup in Analysis 72:513–517, 2012). However, I find that their criticism doesn’t threaten the central idea of my view. In this paper, I make two separate responses that appeal to two unequivocal notions of physical realizers, respectively. I aim to show that a modified argument that uses either notion would work.