This paper investigates spillovers of capital regulation tightening through cross-border lending, focusing on the dynamics of loan spreads in syndicated loans. Utilising a difference- in-difference (DiD) regression approach, we find that, following the implementation of the U.S. stress test in 2009, the spreads on cross-border loans arranged by stress-test banks decreased by 61.8 basis points compared to those arranged by non-stress-test banks. We introduce a novel mechanism to explain this spillover effect: lead arrangers retain higher shares after capital regulation tightening to achieve regulatory arbitrage; participants will thus accept lower loan spreads. This is empirically supported by an 8% increase in lead arranger shares after the stress test implementation. Extending the analysis to non-U.S. countries, we observe a consistent spillover effect. Furthermore, we find that this effect diminishes when regulations are implemented on a consolidated basis or when the borrower's country has also tightened capital regulations; in both situations, cross-border loans are less attractive because regulatory arbitrage cannot be achieved.