diff -r 89038d9ef77d -r 909dc00766a0 src/Pure/Concurrent/unsynchronized.ML
--- a/src/Pure/Concurrent/unsynchronized.ML	Tue Sep 26 14:29:55 2023 +0200
+++ b/src/Pure/Concurrent/unsynchronized.ML	Tue Sep 26 14:42:33 2023 +0200
@@ -39,13 +39,13 @@
 fun add i n = (i := ! i + (n: int); ! i);
 
 fun setmp flag value f x =
-  Thread_Attributes.uninterruptible (fn run => fn () =>
+  Thread_Attributes.uninterruptible_body (fn run =>
     let
       val orig_value = ! flag;
       val _ = flag := value;
       val result = Exn.capture0 (run f) x;
       val _ = flag := orig_value;
-    in Exn.release result end) ();
+    in Exn.release result end);
 
 
 (* weak references *)