Better leave your iPad at home.
Citing "latest security intelligence," United has added "large electronic devices including laptops and tablets" to the list of banned items for match days at its famous 76,100-seater stadium.
An email was circulated to fans ahead of Tuesday's friendly against Valencia, explaining the new measures which aren't believed to be in operation at any other English club.
United says it is a special case.
"The scale of Old Trafford and profile of Manchester United mean that the risk at this venue is unique," United said.
Sports fans are increasingly using iPads and similar devices to take photographs and videos in stadiums, raising fears that games could be filmed and copyright laws could be broken.
Holding up large devices to get a selfie, or a snap of a favourite player or coach, may also restrict the view of spectators nearby.
In 2010, the New York Yankees introduced a policy that prohibited fans from bringing laptops inside Yankee Stadium, and iPads were included in that ban.
Decisions on what can be brought into a football ground in England are a matter for the "relevant stadium management authorities," United said.
The club will, however, still allow the use smart phones and small cameras inside Old Trafford.