Apple has no plans to bring Siri to any other iOS devices apart from the iPhone 4S, an email response to a bug report seems to confirm.
The email, picked up by Apple Insider, was sent by Apple's engineering unit earlier this week.
"Engineering has provided the following feedback regarding this issue: Siri only works with iPhone 4S and we currently have no plans to support older devices," the email reads.
The Siri voice assistant is officially a beta and has suffered a few teething problems since it was introduced with the iPhone 4S last month.
However, it has also won praise, with Consumer Reports yesterday picking out Siri as one of the iPhone 4S' best features.
If you do want to run Siri on older iOS devices, hackers are working on it and two - Steve Troughton-Smith and Grant Paul - claim to have got Siri working on an iPhone 4 and a fourth-generation iPod touch. Troughton-Smith plans to test his solution on the iPhone 3GS this month.