--- a/lib/Test/Nginx.pm
+++ b/lib/Test/Nginx.pm
@@ -180,6 +180,8 @@ sub has_module($) {
 			=> '(?s)^(?!.*--without-stream_map_module)',
 		stream_return
 			=> '(?s)^(?!.*--without-stream_return_module)',
+		stream_set
+			=> '(?s)^(?!.*--without-stream_set_module)',
 		stream_split_clients
 			=> '(?s)^(?!.*--without-stream_split_clients_module)',
 		stream_ssl

new file mode 100644
--- /dev/null
+++ b/stream_set.t
@@ -0,0 +1,66 @@
+#!/usr/bin/perl
+
+# (C) Vladimir Kokshenev
+# (C) Nginx, Inc.
+
+# Tests for stream set directive.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+use Test::Nginx::Stream qw/ stream /;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/stream stream_return stream_set/);
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+stream {
+
+    map 0 $map_var {
+        default "original";
+    }
+
+    server {
+        listen  127.0.0.1:8082;
+        return  $map_var:$set_var;
+
+        set $set_var $map_var;
+        set $map_var "new";
+    }
+
+    server {
+        listen  127.0.0.1:8083;
+        return  $set_var;
+    }
+}
+
+EOF
+
+$t->try_run('no stream set')->plan(2);
+
+###############################################################################
+
+is(stream('127.0.0.1:' . port(8082))->read(), 'new:original', 'set');
+is(stream('127.0.0.1:' . port(8083))->read(), '', 'uninitialized variable');
+
+###############################################################################