PurposeIt is becoming easier for end-users to modify their information system, sometimes against the wishes of management or the original manufacturer. In the mobile device context, “modding”, “jailbreaking” or “rooting” allows a mobile phone user to select operating software and network providers other than those mandated by the original provider. Prior studies have theorised that modders and non-modders possess different perspectives on the relationship between them and their device provider. However, these differences have not been empirically demonstrated in prior work. This paper aims to test theoretical pathways to explain the behavioural relationship effects of security within the modding context.Design/methodology/approachThis study models four relationship conceptualisations from prior research. The study tests this model using a survey of 464 mobile device users to compare the user attitudes of modders and non-modders.FindingsModder and non-modder relationships differ. Both groups value security, but in different ways: modder relationships are governed by satisfaction and commitment, while non-modder relationships are governed more by trust.Originality/valueTo the best of the authors’ knowledge, this is the first study to empirically demonstrate the relationship differences between IS modifiers and non-modifiers. Most published work has focused on IS that are unmodified. Incorporating device modification may improve behavioural understanding of end-users.