diff --git a/src/test/recovery/t/017_shm.pl b/src/test/recovery/t/017_shm.pl
index 633606b2be0bd8e216008b55a21e0f4ef82345f4..70b789f704d673c85d3abba469536b48160fb4d8 100644
--- a/src/test/recovery/t/017_shm.pl
+++ b/src/test/recovery/t/017_shm.pl
@@ -151,7 +151,7 @@ like(slurp_file($gnat->logfile),
 my $single_stderr;
 ok( !run_log(
 		[ 'postgres', '--single', '-D', $gnat->data_dir, 'template1' ],
-		'<', \('SELECT 1 + 1'), '2>', \$single_stderr),
+		'<', \undef, '2>', \$single_stderr),
 	'live query blocks --single');
 print STDERR $single_stderr;
 like($single_stderr, $pre_existing_msg,