The US Senate last month fast-tracked negotiations for the Trans-Pacific Partnership (see go.nature.com/lt2eex), one of the largest free-trade agreements in history. We fear that this could inadvertently fuel the illegal wildlife trade unless strict precautionary measures are put in place.

Last year saw vast increases in rhinoceros and elephant poaching. Liberalized trading could add to this, not least because the trade partnership includes some of the leading consumer and supplier nations of illegal wildlife. Simpler customs procedures, relaxed border controls and trade monitoring all make the smuggling of such products easier.

The agreement should contain negotiated, binding and enforceable clauses that respect international commitments to biodiversity conservation and the regulated trade of protected species. The 2009 US–Peru Trade Promotion Agreement, for example, included obligations and sanctions to uphold Peru's commitment to restrict illegal logging and wildlife trade (see, for instance, S. Jinnah and E. Morgera Rev. Eur. Comp. Int. Environ. Law 22, 324–339; 2013).