Purpose This paper aims to explore the general flaws in the theorization of Islamic economics, particularly its failure to incorporate substantive morality into its framework. Since a considerable number of Islamic economic studies remain within the bounds of instrumental morality, this paper seeks to propose an alternative understanding of Islamic economics by emphasizing the essential role of Islamic moral economy (IME) through substantive morality. Design/methodology/approach The study critically examines the theorization of Islamic economics through a discursive methodology. The adopted method and strategy allow for the discursive evaluation of conceptual developments within the field of modern Islamic economics. It proposes an authentic definition of IME by outlining its paradigmatic framework of political economy, value system, axiomatic approach and operational principles. Findings Islamic economics has been theorized in a reactive and reflexive manner, aiming to provide an alternative to the neoclassical hegemonic discourse. However, it has largely neglected its inherent moral dimension, focusing instead on instrumental morality and failed to embed substantive morality into its system. By introducing an alternative reading of Islamic economics, this study presents IME as a distinct economic model that centers substantive morality in its theorization. Originality/value This paper contributes to the existing literature by offering a novel perspective on Islamic economics that challenges the prevalent instrumental approach and emphasizes the importance of substantive morality. It provides a comprehensive framework for understanding IME as a distinct economic model, thereby enriching the discourse on Islamic economics with an authentic and morally grounded paradigm.