new file mode 100644
--- /dev/null
+++ b/subrequest_output_buffer_size.t
@@ -0,0 +1,85 @@
+#!/usr/bin/perl
+
+# (C) Sergey Kandaurov
+# (C) Nginx, Inc.
+
+# Tests for subrequest_output_buffer_size directive.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/http proxy ssi/)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location / {
+            proxy_pass http://127.0.0.1:8081;
+        }
+
+        location /longok {
+            proxy_pass http://127.0.0.1:8081/long;
+            subrequest_output_buffer_size 42k;
+        }
+
+        location /ssi {
+            ssi on;
+        }
+    }
+
+    server {
+        listen       127.0.0.1:8081;
+        server_name  localhost;
+
+        location / { }
+    }
+}
+
+EOF
+
+$t->write_file('ssi.html',
+	'<!--#include virtual="/$arg_c" set="x" -->' .
+	'set: <!--#echo var="x" -->');
+
+$t->write_file('length', 'TEST-OK-IF-YOU-SEE-THIS');
+$t->write_file('long', 'x' x 40000);
+$t->write_file('empty', '');
+
+$t->try_run('no subrequest_output_buffer_size')->plan(4);
+
+###############################################################################
+
+my ($r, $n);
+
+like(http_get('/ssi.html?c=length'), qr/SEE-THIS/, 'request');
+like(http_get('/ssi.html?c=empty'), qr/200 OK/, 'empty');
+unlike(http_get('/ssi.html?c=long'), qr/200 OK/, 'long default');
+like(http_get('/ssi.html?c=longok'), qr/200 OK/, 'long ok');
+
+###############################################################################