Zephaniah's book tells the story of a 14-year-old Ethiopian who is forced to flee his homeland following a violent civil war. As Alem and his father take flight to London, a litany of thwarted attempts at asylum and institutional red tape ensues.
While Sissay was born near Wigan, his mother left Ethiopia for England. That was in 1966, when she was pregnant with Sissay, who, for most of the next two decades, was shunted from foster home to children's home by a care system that was bound by less explicitly hostile but equally bureaucratic measures.
By his late teens, Sissay was working with a community publishing company in Manchester, and by 21 had published his first book of poems. Tender Fingers In A Clenched Fist was a street-smart collection that could be said to have picked up the mantle of Birmingham-born Zephaniah, who, as the dyslexic son of a Barbadian mother and Jamaican father, published his first book, Pen Rhythm, in 1980 aged 22.
The result of such umbilical cultural and artistic links can be seen in Gail McIntyre's West Yorkshire Playhouse production of Refugee Boy, which opens at the Citizens Theatre tomorrow night, hard on the heels of Glasgow Girls, an even more contemporary refugee-based play. As Sissay himself observes, since he took Zephaniah's story off the page, it too has led something of a nomadic existence.
"Theatre is a sort of refugee in itself," Sissay says. "It comes to a town, sets up home, and then leaves. Fortunately," he stresses, perhaps thinking of some refugees' unhappy experiences in transit, "there is a lot of love around this play."
It is a love that was there from the moment McIntrye first suggested Sissay write the stage version after recognising him as a kindred spirit, both of Zephaniah and Alem.
"Although I was born in the north of England," Sissay says, "I'm both Eritrean and Ethiopian, and I am the only professional writer in the country with that experience, so all these things seemed to fit."
While this may be the case, it begs the question why Zephaniah, whose playwriting has gone hand in hand with his poetry ever since his first stage work, Playing The Right Tune, appeared in London and Edinburgh in 1985, did not opt to do it himself?
"That is a serious question," Sissay says. "Benjamin is probably one of the five most famous black poets in the country, and is also respected as a thinker, so being asked to do something like that is an honour.
"Doing an adaptation is like a musical remix, so even though it was a bit scary, having watched Benjamin go from poet to novelist with this book that adults read as well as teenagers, I really had to inhabit it, and Benjamin just let me get on with it."
Sissay relates the art of adapting other people's work by way of an encounter with best-selling Australian writer Peter Goldsworthy.
"One of his short stories was made into a film," Sissay says, "and he said that to truly adapt a text, you have to disrespect the original and grab hold of it. It sounds terrible, but it is a creative exercise. You have got to tear it apart, find its heart and grow a body around it."
Like Zephaniah, Sissay draws inspiration from black writers such as Linton Kwesi Johnson, the Jamaican-born, Brixton-raised poet whose 1978 album Dread Beat An Blood did much to popularise both dub reggae and poetry as a performed form.
If Zephaniah and the late Michael Smith can be said to be the next generation, Sissay and the likes of Jackie Kay, who was born to a Scottish mother and a Nigerian father, have continued the tradition of a black English and Scottish poetic diaspora.
"Coming to Scotland was a rites of passage," says the Canongate-published author, who spent six of the 12 years he was in foster care in Scotland. "I was brought up in England, was the only black kid in the village and became other people's experiment. Race was more of an issue then than now. Boys would give me nicknames, spit on the back of my coat or just pick a fight. What hurt me wasn't just the personal racism, but also the institutionalised racism.
"Oddly, I always used to think Scotland was more racist than England, even though my grandfather was called Duncan Munro. Then I came up to the Edinburgh Festival when I was about 19, and I thought the people were so tuned in. I have never felt safer, and I realised not all white people were racist. Then I went to Mayfest in Glasgow, and to St Andrews, and I realised the Celts really have it going on."
Rascism, however, still exists, as recent events in Glasgow testify to. These include the filmed abuse of a Nigerian busker by two white men that was broadcast in TV documentary The Street while a man was recently arrested for allegedly abusing Glasgow MSP Humza Yousaf who was selling The Big Issue outside Queen Street Station.
"You could say racism is an act of insecurity," says Sissay, "and it is something every new generation of immigrants has to face, with some people from previous generations being prejudiced towards them. It is easy to slip into this attitude, and it is something you have to fight against. It is the power of art that can make us realise that.
"In Refugee Boy, Alem and his father are told they are not one of us any more, and are not wanted here. That can happen on a turn of a button, and you become the enemy. These people have not done anything wrong. They have just been born into a set of historical events they have no power over."
The day before we talk, Sissay took part in an open forum that looked at the questions of race and diversity in theatre. The event was attended by 150 people, with speakers including former National Theatre Of Scotland director Vicky Featherstone.
"It was such a warm, honest idea," Sissay says, "and it reminded me that the idea of diversity is about appreciating the other, and being open to a person to make life better. Diversity is much bigger than being black or white, but is about the idea that the world is your oyster."
Refugee Boy, Citizens Theatre, Glasgow, tomorrow to Saturday.