new file mode 100644
--- /dev/null
+++ b/proxy_cache_min_free.t
@@ -0,0 +1,76 @@
+#!/usr/bin/perl
+
+# (C) Sergey Kandaurov
+# (C) Nginx, Inc.
+
+# Tests for http proxy cache, min_free parameter.
+
+###############################################################################
+
+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 cache/)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    proxy_cache_path   %%TESTDIR%%/cache  levels=1:2 min_free=4k
+                       keys_zone=NAME:1m;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location / {
+            proxy_pass    http://127.0.0.1:8081;
+
+            proxy_cache   NAME;
+
+            proxy_cache_valid   any      1m;
+
+            add_header X-Cache-Status $upstream_cache_status;
+        }
+    }
+
+    server {
+        listen       127.0.0.1:8081;
+        server_name  localhost;
+
+        location / { }
+    }
+}
+
+EOF
+
+$t->write_file('t.html', 'SEE-THIS');
+$t->try_run('no proxy_cache_path min_free')->plan(2);
+
+###############################################################################
+
+like(http_get('/t.html'), qr/SEE-THIS/, 'proxy request');
+
+$t->write_file('t.html', 'NOOP');
+like(http_get('/t.html'), qr/SEE-THIS/, 'proxy request cached');
+
+###############################################################################