The academy graduate has impressed manager Peter Jackson this term with his progress on the pitch, but his recent form has been hindered by his injury.
"I'm delighted to give Adnan his contract extension," said Jackson."He's got a terrific attitude and this is his reward for that.
"He has come on very well since the start of the season. He's definitely got something and I would like to see him realise that potential.
"He has been playing well in the reserves and has scored a few but has been in some discomfort recently so we decided it was time it was sorted.
"He will go for an operation next week which should hopefully sort the problem out."
Meanwhile, Jackson confirmed young defender Nathan Clarke required an ankle operation after picking up an injury against Rochdale.
"The injury resulted in damage to the band of tissue that holds ankle tendons in behind the ankle bone," he added.
"The tendons moved from behind the ankle bone to on top of it meaning surgery was necessary to put the tendons back in the correct position."
