Adaptive action-related reactions to errors, i.e. (meta-)cognitive processes and behaviours directly aimed at overcoming an error, have been proposed to benefit learning outcomes. However, causally interpretable findings are sparse in the current literature. Addressing this research deficit, the present study aimed at investigating whether action-related error adaptivity during the learning process facilitates knowledge acquisition in an actual learning situation. Data of 177 undergraduate students was analysed in structural equation models. Adaptive action-related reactions to errors were simultaneously assessed via self-reports and a behavioural indicator (voluntary repetitions of previous learning material after errors). Both forms of operationalisation were positively correlated and revealed similar result patterns. In two separate models, self-reported as well as behavioural adaptive action-related reactions to errors indicated a positive effect on knowledge acquisition. These findings further validate the self-report measurement of action-related error adaptivity and point to its direct impact on the learning outcome.