Previous research indicates that academic emotions are largely organized along domain-specific lines. In the present study (N = 1,687; Grades 8/11), the authors explored the domain specificity of academic emotions in terms of the moderating influence of having the same versus a different course instructor across domains. The authors evaluated discrete emotions consisting of enjoyment, pride, anxiety, anger, and boredom as experienced in the academic domains of mathematics and physics. Consistent with previous findings, between-domain relations for these emotions were relatively weak. These relations were, however, significantly stronger in classes having the same instructor in mathematics and physics compared with classes having different instructors for each subject. Nevertheless, the between-domain relations in classes having the same instructor were not strong enough to disconfirm the domain-specific conceptualization of academic emotions. Last, the authors discuss directions for future research on additional factors potentially affecting the strength of between-domain relations of academic emotions. (Contains 1 footnote and 3 tables.)