The prolonged absence of the late Nigerian President Umaru Musa yar'Adua from the country for almost six months has prompted the amendment of the constitution.
By the new amendment, the proposal is that by a simple majority, the National Assembly can mandate the vice president to perform the duties of the president, should the president be incapable of doing so, within 21 days.
Before now, the constitution did not state how long a sitting president could be away from the country without power shifting to the vice president.
Now the two chambers of parliament, the Senate and House of Representatives, have identified this gap in the constitution and proposed an amendement.
When Yar'Adua was unable to perform his duties, the National Assembly used what they called "doctrine of necessity" to declare the then vice president, Goodluck Jonathan as acting president.
The National Assembly has voted to amend 40 sections of the 1999 Nigerian constitution.
These amemendments have to be presented to to all 36 Houses of Assembly in the country before they can be accepted.