diff --git a/src/uri.cc b/src/uri.cc
index 6c4b4685..475b7663 100644
--- a/src/uri.cc
+++ b/src/uri.cc
@@ -238,6 +238,41 @@ bool parse(UriStruct& result, const std::string& uri)
   return true;
 }
 
+std::string construct(const UriStruct& us)
+{
+  std::string res;
+  res += us.protocol;
+  res += "://";
+  if(!us.username.empty()) {
+    res += util::percentEncode(us.username);
+    if(us.hasPassword) {
+      res += ":";
+      res += util::percentEncode(us.password);
+    }
+    res += "@";
+  }
+  if(us.ipv6LiteralAddress) {
+    res += "[";
+    res += us.host;
+    res += "]";
+  } else {
+    res += us.host;
+  }
+  uint16_t defPort= FeatureConfig::getInstance()->
+    getDefaultPort(us.protocol);
+  if(us.port != 0 && defPort != us.port) {
+    res += ":";
+    res += util::uitos(us.port);
+  }
+  res += us.dir;
+  if(us.dir.empty() || us.dir[us.dir.size()-1] != '/') {
+    res += "/";
+  }
+  res += us.file;
+  res += us.query;
+  return res;
+}
+
 } // namespace uri
 
 } // namespace aria2
diff --git a/src/uri.h b/src/uri.h
index 48ed3562..c51be38e 100644
--- a/src/uri.h
+++ b/src/uri.h
@@ -67,6 +67,8 @@ struct UriStruct {
 // undefined.
 bool parse(UriStruct& result, const std::string& uri);
 
+std::string construct(const UriStruct& us);
+
 } // namespace uri
 
 } // namespace aria2
diff --git a/test/UriTest.cc b/test/UriTest.cc
index 9c65cfb7..025f41ca 100644
--- a/test/UriTest.cc
+++ b/test/UriTest.cc
@@ -33,6 +33,7 @@ class UriTest:public CppUnit::TestFixture {
   CPPUNIT_TEST(testSetUri_zeroUsername);
   CPPUNIT_TEST(testSetUri_ipv6);
   CPPUNIT_TEST(testInnerLink);
+  CPPUNIT_TEST(testConstruct);
   CPPUNIT_TEST_SUITE_END();
   
 public:
@@ -60,6 +61,7 @@ public:
   void testSetUri_zeroUsername();
   void testSetUri_ipv6();
   void testInnerLink();
+  void testConstruct();
 };
 
 
@@ -384,6 +386,90 @@ void UriTest::testInnerLink()
   CPPUNIT_ASSERT_EQUAL(std::string(""), us.query);
 }
 
+void UriTest::testConstruct()
+{
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host/dir/file?q=abc#foo"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/dir/file?q=abc"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host/dir/file"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/dir/file"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host/dir/"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/dir/"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host/dir"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/dir"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host/"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    us.protocol = "http";
+    us.host = "host";
+    us.file = "foo.xml";
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/foo.xml"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host:80"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host/"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://host:8080"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://host:8080/"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "http://[::1]:8000/dir/file"));
+    CPPUNIT_ASSERT_EQUAL(std::string("http://[::1]:8000/dir/file"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "ftp://user%40@host/dir/file"));
+    CPPUNIT_ASSERT_EQUAL(std::string("ftp://user%40@host/dir/file"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "ftp://user:@host/dir/file"));
+    CPPUNIT_ASSERT_EQUAL(std::string("ftp://user:@host/dir/file"),
+                         construct(us));
+  }
+  {
+    UriStruct us;
+    CPPUNIT_ASSERT(parse(us, "ftp://user:passwd%40@host/dir/file"));
+    CPPUNIT_ASSERT_EQUAL(std::string("ftp://user:passwd%40@host/dir/file"),
+                         construct(us));
+  }
+}
+
 } // namespace uri
 
 } // namespace aria2