diff -U3 /tmp/cirrus-ci-build/src/test/regress/expected/pg_ndistinct.out /tmp/cirrus-ci-build/build-32/testrun/recovery/027_stream_regress/data/results/pg_ndistinct.out
--- /tmp/cirrus-ci-build/src/test/regress/expected/pg_ndistinct.out	2025-11-18 09:14:55.163836974 +0000
+++ /tmp/cirrus-ci-build/build-32/testrun/recovery/027_stream_regress/data/results/pg_ndistinct.out	2025-11-18 09:25:18.188073696 +0000
@@ -123,22 +123,22 @@
 ERROR:  malformed pg_ndistinct: "[{"\ud83d\ude04\ud83d\udc36" : [1, 2], "ndistinct" : 4}]"
 LINE 1: SELECT '[{"\ud83d\ude04\ud83d\udc36" : [1, 2], "ndistinct" :...
                ^
-DETAIL:  Only allowed keys are "attributes" and "ndistinct".
+DETAIL:  Must be valid JSON.
 SELECT '[{"attributes" : [1, 2], "\ud83d\ude04\ud83d\udc36" : 4}]'::pg_ndistinct;
 ERROR:  malformed pg_ndistinct: "[{"attributes" : [1, 2], "\ud83d\ude04\ud83d\udc36" : 4}]"
 LINE 1: SELECT '[{"attributes" : [1, 2], "\ud83d\ude04\ud83d\udc36" ...
                ^
-DETAIL:  Only allowed keys are "attributes" and "ndistinct".
+DETAIL:  Must be valid JSON.
 SELECT '[{"attributes" : [1, 2], "ndistinct" : "\ud83d\ude04\ud83d\udc36"}]'::pg_ndistinct;
 ERROR:  malformed pg_ndistinct: "[{"attributes" : [1, 2], "ndistinct" : "\ud83d\ude04\ud83d\udc36"}]"
 LINE 1: SELECT '[{"attributes" : [1, 2], "ndistinct" : "\ud83d\ude04...
                ^
-DETAIL:  Invalid "ndistinct" value.
+DETAIL:  Must be valid JSON.
 SELECT '[{"attributes" : ["\ud83d\ude04\ud83d\udc36", 2], "ndistinct" : 1}]'::pg_ndistinct;
 ERROR:  malformed pg_ndistinct: "[{"attributes" : ["\ud83d\ude04\ud83d\udc36", 2], "ndistinct" : 1}]"
 LINE 1: SELECT '[{"attributes" : ["\ud83d\ude04\ud83d\udc36", 2], "n...
                ^
-DETAIL:  Invalid "attributes" value.
+DETAIL:  Must be valid JSON.
 -- Valid keys, invalid values
 SELECT '[{"attributes" : null, "ndistinct" : 4}]'::pg_ndistinct;
 ERROR:  malformed pg_ndistinct: "[{"attributes" : null, "ndistinct" : 4}]"