Computing education in England's schools is going through a revolution, but there is evidence that too few pupils want to be part of it.
Figures from the Office of Qualifications and Examinations Regulation (Ofqual) show only a modest rise in students taking the new computer science GCSE.
Experts are concerned.
The British Computer Society warns the number studying for a computing qualification could halve by 2020.
The organisation - which is the professional body for the IT industry - says that would be a disaster for the economy.
The old ICT course, which was the main way school students learned about computing, is being scrapped, with the last GCSE entrants taking the exam next year. The subject, which was described by critics as teaching little more than how to use Microsoft Office, is being replaced by the more rigorous computer science GCSE.
But figures from Ofqual showing entries for the exam rising to 67,800 this year from 61,220 in 2016 have set alarm bells ringing. With 58,600 still taking the ICT exam, the overall number getting a GCSE computing qualification has fallen slightly.
The British Computing Society says that when ICT disappears, the computer science exam will fail to fill the gap.
"If we don't act now," says Bill Mitchell from the BCS, "by 2020 we are likely to see the number of students studying computing at GCSE halve, when it should be doubling. If that happens, it will be a disaster for our children, and the future of the nation."
The other big concern is that too few girls are taking up the computer science exam - in 2016 they made up just 20% of entrants, while the figure for ICT has been around 40%.
Prof Rose Luckin says the subject has an image problem.
"Computer science is seen as more 'techie' and it is still dominated by men," explains the expert from University College London's Knowledge Lab, who has been researching and writing about the teaching of technology for 20 years.
"Many girls believe computer science and coding is 'for boys' and they do not see desirable career options that appeal to them."
What seems clear is that the computer science exam is far more challenging, both for students and teachers. That was of course the aim, but those who warned that ending ICT risked throwing the baby out with the bathwater may now feel vindicated.
Drew Buddie, who is head of computing at a school near London, has always argued that ICT was unfairly maligned and was far more creative than its critics assumed.
Now, he says, "it is clear that many 14-to-17-year-old students, particularly girls, are not attracted to such a specific and narrow course."
"The current GCSE in computer science has replaced the opportunities for creativity that existed in ICT with set programming tasks that have very few solutions," he adds.
The British Computing Society, which lobbied for the new GCSE, insists that it always argued for a new IT qualification to complement computer science, but that was rejected by ministers.
The organisation says it is unrealistic to expect teachers of ICT to turn into teachers of computer science without significant training and support - and despite initiatives from organisations like Computing At School there has just not been enough funding to usher in this revolution.
I put some of these criticisms to the Department for Education. A spokesman stressed that the new exam had been designed with industry experts to develop the computational skills needed for today's economy.
He pointed out that the numbers taking it had more than doubled since 2015 and said "we expect that number to continue to rise while ICT GCSE is phased out. We are continuing to work to encourage even greater uptake of computer science, especially among girls."
But Prof Luckin says the situation is urgent.
"We need to focus on understanding exactly why students are not attracted to computer science so that we can ensure an appropriately skilled workforce for the future, not least amongst the teaching profession," she says.
And she adds that the advent of artificial intelligence makes this mission even more vital.
Five years ago, it seemed just about everyone, from teachers to business leaders to politicians, was in agreement about the need for radical changes in the way children were taught about computers.
But today it is hard to find many who are happy with the speed and direction of the revolution in computing education.