Apple may have shot some jabs at Microsoft during its “Let Us Loop You In” event on Monday, but that hasn’t stopped the company from promoting its rival’s software.

Observers over at The Verge, as well as former Microsoft Windows division president Steven Sinofsky, noticed Apple has quietly started promoting Office 365 as an add-on for its iPad Pro.

After choosing any iPad Pro from Apple’s AAPL website, Fortune was able to confirm that on the iPhone maker’s “accessories” page, it lists Microsoft’s MSFT Office 365 as a worthy add-on to the purchase. Customers can choose from Office 365 Personal, Home, or University.

The finding is notable considering how hard Apple came down on Microsoft on Monday at its special press event. During his talk at the keynote, Apple senior vice president of worldwide marketing Phil Schiller took several shots at Microsoft, remarking that over 600 million computers that are over five years old are currently running Windows. Schiller derided it as “really sad.” He added, along with CEO Tim Cook, that Apple wants its iPad Pro to be the replacement for those tired, old Windows PCs.

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“We think that whether you already have an iPad or whether it’s time to replace that PC laptop, the iPad Pro is an amazing choice that allows you to do so much more,” Cook said during his own remarks.

Apple has been selling a 12.9-inch iPad Pro for months. Despite Schiller saying that the majority of iPad Pro customers “are coming from a Windows PC,” there are no signs of Apple’s iPad business turning around. Indeed, during its last-reported quarter ended December 26, Apple’s iPad revenue was down 21% year-over-year. The company’s unit sales plummeted 25% over the same period.

In a bid to stem its losses, Apple announced a 9.7-inch iPad Pro at its Monday event. Like its bigger alternative, the 9.7-inch version is designed for corporate customers, and Apple pitched it a suitable replacement for lightweight notebooks thanks to its support for the Smart Keyboard, which boasts both a stand and a physical keyboard in one.

Apple’s desire to hit Microsoft hard could have something to do with recent surveys suggesting Microsoft’s mobile devices may be registering more sales than Apple’s iPad. In December, for instance, data analytics company 1010data said Microsoft’s tablets, including the Surface Pro 4 and Surface Book laptop-tablet hybrid, earned 45% share of U.S. online tablet sales in October, topping Apple’s 17% share. It was the first time Microsoft won a month against Apple.

The corporate world has been central to Microsoft’s success. Companies are still stubbornly committed to Windows and the many platforms that are offered in Office 365, including Word, Excel, and Outlook. Apple is also trying to grow its presence in the enterprise. On Monday, Apple used its anti-Microsoft rhetoric to make a case that the iPad Pro could be an ideal alternative specifically for Microsoft products.

Read more: Apple Goes All Out On Rival Microsoft

Apple’s decision to offer Office 365 as an accessory for the iPad Pro, however, suggests that the company still needs Microsoft’s help if it’s ever to grow its presence in the corporate world. While Apple has its own slate of “productivity” apps, including Pages and Numbers, they’ve never quite caught on in the corporate world. Showing Office 365 as an add-on for the iPad Pro could be Apple’s way of acknowledging that Office 365 is an important piece of the corporate pie. And like it or not, Apple must accept that.

Meanwhile, somewhere, someone at Microsoft has to be snickering.