Conditional reasoning tests (CRT) were proposed as an innovative approach to implicitly measure the rationalizations toward counterproductive work behaviors (CWB) often associated with overt integrity tests. The authors first set out to map a typology of justification mechanisms for general CWB, and to then validate a new integrity‐based CRT in both honest and faking testing conditions. Unfortunately, while demonstrating encouraging construct and criterion validity in the honest testing condition, the test was less resistant to faking than originally anticipated, and ceased to be valid in the faking condition. Overall, the results provide theoretical insight toward understanding how employees justify CWB, but raise concerns regarding the potential operational limitations of at least some CRTs.