Some 800,000 people were killed during Rwanda's 1994 genocide
Genocide criminals in Rwanda will have to serve life sentences in solitary confinement, under legislation approved the lower house of parliament.
The proposed sentence, which must be formally approved by the senate and president, follows Rwanda's abolishing of the death penalty in 2007.
It is intended for use in the case of those convicted of genocide, as well as rape and gang-related crimes.
Critics have said the judicial sentence could lead to human rights abuses.
A copy of the draft law says prisoners will not be subject to degrading treatment and will be in cells with adequate space and light.
The BBC's Geoffrey Mutagoma in the capital, Kigali, says that under the plans, certain prisoners would be confined in maximum security cells and prevented from interacting with other inmates at any point.
Analysts expect the passing of the bill to be a mere formality.
Rwanda abolished the death penalty two years ago after some countries said it would be an obstacle to the extradition of genocide suspects to Rwanda.
The parliament's move came as Sweden's Supreme Court ruled on Wednesday in favour of the extradition of a Rwandan genocide suspect.
The 53-year-old suspect, Sylvere Ahorugeze, a former director of Rwanda's civil aviation authority, is accused of participating in the 1994 slaughter.
The extradition must yet be confirmed by the Swedish justice ministry.
It has been estimated that Hutu extremists killed up to 800,000 people, mainly minority Tutsis and moderate Hutus, during the 100-day genocide.