diff --git a/nginx/nginx-lib.pl b/nginx/nginx-lib.pl
index fd6055628..c36dbb80e 100644
--- a/nginx/nginx-lib.pl
+++ b/nginx/nginx-lib.pl
@@ -551,8 +551,11 @@ if ($lock_all_config_files_depth) {
 my $main = &resolve_links($config{'nginx_config'}) || $config{'nginx_config'};
 my @files = ($main);
 my %locked;
-while (@files) {
+# Repeat until a fresh parse finds no additional config files.
+while (1) {
+	my $new_files = 0;
 	foreach my $f (@files) {
+		next if ($locked{$f});
 		my $pid = &test_lock($f);
 		if ($pid && $pid == $$) {
 			# Keep a lock taken by the caller outside our unlock list.
@@ -564,12 +567,15 @@ while (@files) {
 			&error("Failed to lock Nginx config file $f");
 			}
 		$locked{$f} = 1;
+		$new_files++;
 		&unflush_file_lines($f);
 		}
-	# Raw config edits lock included files independently. Re-read after
-	# acquiring each batch and lock any newly discovered includes.
+	last if (!$new_files);
+
+	# An included file may change while this process waits for its lock.
+	# Reparse after each batch to find any newly included files.
 	&flush_config_cache();
-	@files = grep { !$locked{$_} } &unique(&get_all_config_files(),
+	@files = &unique(&get_all_config_files(),
 		$parent ? &get_all_config_files($parent) : ());
 	}
 $lock_all_config_files_depth = 1;
diff --git a/nginx/t/config-locks.t b/nginx/t/config-locks.t
index 3fa9110d6..8f8fbb069 100644
--- a/nginx/t/config-locks.t
+++ b/nginx/t/config-locks.t
@@ -163,4 +163,23 @@ subtest 'included files are refreshed after waiting for their locks' => sub {
 	main::unlock_all_config_files();
 };
 
+subtest 'a parent block can span included files' => sub {
+	write_text($included, "listen 80;\n");
+	write_text($conf,
+		"http {\n".
+		"    server {\n".
+		"        server_name parent.invalid;\n".
+		"        include $included;\n".
+		"    }\n".
+		"}\n");
+	main::flush_config_cache();
+	my $parent = server('parent.invalid');
+	is_deeply([sort(main::get_all_config_files($parent))],
+		[sort($conf, $included)], 'parent spans both config files');
+	main::lock_all_config_files($parent);
+	ok(-e "$conf.lock" && -e "$included.lock",
+		'parent lock covers both config files');
+	main::unlock_all_config_files();
+};
+
 done_testing();