diff -r 02d9844ff892 -r 6f2bcdfa9a19 src/HOL/Tools/record.ML
--- a/src/HOL/Tools/record.ML	Wed Jan 22 21:35:05 2025 +0100
+++ b/src/HOL/Tools/record.ML	Wed Jan 22 22:22:19 2025 +0100
@@ -1504,7 +1504,7 @@
     val (x, ca) =
       (case rev (drop (length params) ys) of
         [] => (head_of (fst (HOLogic.dest_eq (HOLogic.dest_Trueprop
-          (hd (rev (Logic.strip_assums_hyp (hd (Thm.prems_of rule')))))))), true)
+          (hd (rev (Logic.strip_assums_hyp (hd (Thm.take_prems_of 1 rule')))))))), true)
       | [x] => (head_of x, false));
     val rule'' =
       infer_instantiate ctxt