Shares of cybersecurity firm Fortinet sank in after hours trading despite an improved outlook for the fourth quarter and the year.

The stock was down more than 24% in late trading after closing the regular session down 5.9%.

The company reported adjusted earnings of 91 cents a share and revenue of $2.08 billion, a gain of 20.5% from a year ago. Wall Street had expected adjusted earnings of 86 cents a share and revenue of $2.06 billion.

For the fourth quarter, Fortinet sees adjusted profit of 93 cents to 95 cents a share and revenue in a range of $2.155 billion to $2.245 billion, versus expectations for earnings of 88 cents a share and revenue of $2.16 billion. It sees fourth quarter billings in a range of $2.775 billion to $2.925 billion.

It also raised its guidance for the full year, forecasting adjusted earnings of $3.54 to $3.58 a share and revenue of $8.125 billion to $8.215 billion versus expectations for profit of $3.45 a share and revenue of $8.12 billion.

CEO Ken Xie said that as artificial intelligence introduces new attack surfaces, network security remains the critical foundation of AI security. Demand for security products has allowed Fortinet to raise its billings guidance for the third time this year, he noted.

Fortinet sees billings for the year in the range of $9.568 billion to $9.718 billion.