French aerospace and defence group Thales is procuring cybersecurity company Imperva from Thoma Bravo in a deal worth $3.6 billion.

The news comes four years after private equity giant Thoma Bravo acquired Imperva for $2.1 billion, taking the San Mateo-based company private eight years after it had gone public on the New York Stock Exchange (NYSE).

Founded in 2002, Imperva is a data and application security company with services spanning web application firewalls (WAFs), API security, DDoS protection, account takeover (ATO) protection, data activity monitoring (DAM), and more.

Thales has expended considerable resources in recent years bolstering its cybersecurity offerings through acquisitions. This includes a $5.5 billion deal in 2017 to procure Gemalto, a company offering digital identification and data protection for industries such as banking. And more recently it acquired both Excellium and and S21SEC, deals which closed last year. Thales is also in the process of acquiring Australian cybersecurity startup Tesserent, in a deal worth $176 million (AUD).

With Imperva under its wing, this signals Thales entry to the application security market specifically, while it’s also now expanding its existing footprint in the data security sphere.

“With this acquisition, we are seizing a unique opportunity to accelerate our cybersecurity capabilities and are taking an important step towards our ambition to build a world-class global cybersecurity integrated player, providing a comprehensive portfolio of products and services,” Thales CEO Patrice Caine said in a press release.

Thales said that with Imperva on board, its total cybersecurity business will generate north of €2.4 billion ($2.65 billion) in revenues, with Imperva contributing some $500 million itself.

Thales says it expects to close the deal by early 2024.