We study the impact of mandated broker-dealer (BD) audit improvements focusing on in- ternal controls testing on insider stock gift backdating following the implementation of more stringent internal controls testing by auditors in 2011. Comparing BDs with auditors al- ready subject to PCAOB oversight (control) to those newly subject to PCAOB requirements (treatment), we find increased oversight and record-keeping standards reduce backdating. We find larger treatment effects for BDs offering more services, with a higher fraction of employees with some misconduct history, that are privately owned, and with longer audi- tor relationships whose auditors also had fewer clients. Overall, insider stock gifts decrease post-implementation, underscoring the importance of robust internal controls and regulatory oversight.