This study presents a simple model of corporate debt dynamics within the framework ofthe post-Keynesian theory of growth and distribution. Our model introduces corporate debtdynamics into a modified version of Lavoie’s Minsky–Steindl model, yielding long-runresults different from those of Lavoie (1995) and Hein (2007) by showing that a stablelong-run equilibrium exists in both puzzling and normal cases. On the basis of these results,this study shows that Minsky’s financial instability as well as Steindl’s paradox of debt as aphenomenon of macroeconomic instability can be formulated within the framework of apost-Keynesian debt dynamics system.