Despite evidence that the accurate assessment of occupational health should include measures of both generic job demands and occupation-specific job demands, most research includes only generic job demands. The inclusion of more focused occupation-specific job demands is suggested to explain a larger proportion of variance for both direct effects and job demands × job control/support interaction effects, as compared with the inclusion of generic job demands. This research tested these two propositions via a self-report survey assessing key psychological job characteristics administered twice to a sample of correctional workers (N = 746). The research clearly identified that the assessment of correctional-specific job demands (CJD) was more strongly associated with job satisfaction, work engagement, turnover intentions and psychological strain, as compared with an assessment of generic job demands. However, the CJD did not produce a greater proportion of significant job demands × job control/support interaction effects, as compared with the generic job demands measure. The results thereby provide further support for the acknowledged ‘elusiveness’ of these theoretical interactions. Overall, however, the results did support the inclusion of occupation-specific measures of job demands for the accurate assessment of the health and job performance of high-risk workers. The implications for theoretical discussions that describe how high job demands are moderated by job resources are discussed. Copyright © 2013 John Wiley & Sons, Ltd.