Humza Yousaf has said no problems were reported about Covid vaccine passports at Celtic's Europa League match - the first major test of the scheme since enforcement became mandatory.
The Scottish Government requires people going to nightclubs and large events to prove they are fully vaccinated, although the rules only started to be enforced from Monday after an 18-day "grace period".
Asked about how the controversial scheme worked at Tuesday afternoon's match at Celtic Park with 50,427 fans in attendance, the Health Secretary said there had been "no issues".
Speaking to the PA news agency at the opening of the NHS Scotland Academy to train healthcare workers, Mr Yousaf added: "I have had feedback from the Celtic game and it's been very positive.
"There were no issues at all with the checks and no issues in terms of the crowd who were very compliant when asked to show their status records.
"So far, so good.
"Another challenge will be the weekend up ahead."
Mr Yousaf then urged Scots to update the app after changes were made to ensure it still works, explaining it will then only show a QR code rather than the vaccine used and when it was administered.
He added: "Essentially what it will do is that when a business, someone at the turnstiles or the door, verifies you, your app comes up with limited information and then a green tick.
"It will be helpful for the business, but also give additional reassurance to the person that there's less information about them for the person at the door to see."
He also defended the robustness of the app's "inbuilt security", despite the app allowing QR codes to be screenshotted and shared, suggesting it is unlikely security guards will be fooled.
"If you're going to be fraudulently using the vaccine passport, you may be committing an offence - that's the first thing to say," Mr Yousaf told PA.
"The person at the door will have been trained to spot [the security feature of a shimmering aeroplane].
"So if you try to do that, I don't think your chances are very good."
