Barclays Plc has warned bankers who have left the company not to try to poach their former colleagues, according to a report by the Financial Times.

The UK lender, which for years has had global ambitions, is struggling to stem a flow of departures from its US arm, the newspaper reported. Around 30 bankers, including global investment banking chair John Miller and top dealmaker Marco Valla, have left this year to join rival firms such as Jefferies and UBS.

Barclays’ human resources department has been warning bankers about poaching their old workmates, the FT reported, citing unidentified people familiar with the matter.

Read more: Barclays CEO Addresses Dealmaker Exits in Virtual Town Hall

In response to the exodus, Barclays has hired roughly 20 bankers at the director and managing-director level, including Douglas Melsheimer from Goldman Sachs Group Inc.

Barclays is confident in its strategy and will “continue to invest in talent,” the FT cited the bank as saying in a statement.