--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -120,6 +120,22 @@
 command_ok(
 	[ 'pg_ctl', '-D', $node->data_dir, '-l', $node->logfile, 'restart' ],
 	'restart succeeds with correct SSL protocol bounds');
+
+# Test parsing colon-separated groups in ssl_ecdh_curve. Writing to
+# sslconfig.conf ensures these values get overwritten by the next call to
+# switch_server_cert (which truncates and rewrites sslconfig.conf).
+$node->append_conf('sslconfig.conf', qq{ssl_ecdh_curve='bad:value'});
+my $log_size = -s $node->logfile;
+command_fails(
+	[ 'pg_ctl', '-D', $node->data_dir, '-l', $node->logfile, 'restart' ],
+	'restart fails with incorrect ECDH groups');
+ok( $node->log_contains(
+		qr/ECDH: could not set group names from ssl_ecdh_curve/, $log_size),
+	'error message mentions ssl_ecdh_curve');
+$node->append_conf('sslconfig.conf', qq{ssl_ecdh_curve='prime256v1'});
+command_ok(
+	[ 'pg_ctl', '-D', $node->data_dir, '-l', $node->logfile, 'restart' ],
+	'restart succeeds after correcting ssl_ecdh_curve');
 
 ### Run client-side tests.
 ###

--- a/src/test/ssl/t/SSL/Server.pm
+++ b/src/test/ssl/t/SSL/Server.pm
@@ -299,6 +299,8 @@
 	open my $sslconf, '>', "$pgdata/sslconfig.conf";
 	print $sslconf "ssl=on\n";
 	print $sslconf $backend->set_server_cert(\%params);
+	# use lists of ECDH curves for syntax testing
+	print $sslconf "ssl_ecdh_curve='prime256v1:secp521r1'\n";
 	print $sslconf "ssl_passphrase_command='"
 	  . $params{passphrase_cmd} . "'\n"
 	  if defined $params{passphrase_cmd};