diff --git a/tests/test-http-req.cpp b/tests/test-http-req.cpp
index 484a7ad6..10ea621f 100644
--- a/tests/test-http-req.cpp
+++ b/tests/test-http-req.cpp
@@ -3,11 +3,12 @@
 
 using namespace i2p::http;
 
-int main(int argc, char *argv[]) {
+int main() {
   HTTPReq *req;
   int ret = 0, len = 0;
   const char *buf;
 
+  /* test: parsing request with body */
   buf =
     "GET / HTTP/1.0\r\n"
     "User-Agent: curl/7.26.0\r\n"
@@ -31,6 +32,7 @@ int main(int argc, char *argv[]) {
   assert(req->headers.find("User-Agent")->second == "curl/7.26.0");
   delete req;
 
+  /* test: parsing request without body */
   buf =
     "GET / HTTP/1.0\r\n"
     "\r\n";
@@ -44,6 +46,7 @@ int main(int argc, char *argv[]) {
   assert(req->headers.size() == 0);
   delete req;
 
+  /* test: parsing request without body */
   buf =
     "GET / HTTP/1.1\r\n"
     "\r\n";
@@ -52,6 +55,7 @@ int main(int argc, char *argv[]) {
   assert((ret = req->parse(buf, len)) == -1); /* no host header */
   delete req;
 
+  /* test: parsing incomplete request */
   buf =
     "GET / HTTP/1.0\r\n"
     "";
@@ -60,6 +64,7 @@ int main(int argc, char *argv[]) {
   assert((ret = req->parse(buf, len)) == 0); /* request not completed */
   delete req;
 
+  /* test: parsing slightly malformed request */
   buf =
     "GET http://inr.i2p HTTP/1.1\r\n"
     "Host:  stats.i2p\r\n"
diff --git a/tests/test-http-res.cpp b/tests/test-http-res.cpp
index 6188a68d..7dd74e1e 100644
--- a/tests/test-http-res.cpp
+++ b/tests/test-http-res.cpp
@@ -3,11 +3,12 @@
 
 using namespace i2p::http;
 
-int main(int argc, char *argv[]) {
+int main() {
   HTTPRes *res;
   int ret = 0, len = 0;
   const char *buf;
 
+  /* test: parsing valid response without body */
   buf =
     "HTTP/1.1 304 Not Modified\r\n"
     "Date: Thu, 14 Apr 2016 00:00:00 GMT\r\n"
@@ -31,6 +32,18 @@ int main(int argc, char *argv[]) {
   assert(res->length() == 536);
   delete res;
 
+  /* test: building request */
+  buf =
+    "HTTP/1.0 304 Not Modified\r\n"
+    "Content-Length: 0\r\n"
+    "\r\n";
+  res = new HTTPRes;
+  res->version = "HTTP/1.0";
+  res->code = 304;
+  res->status = "Not Modified";
+  res->add_header("Content-Length", "0");
+  assert(res->to_string() == buf);
+
   return 0;
 }
 
diff --git a/tests/test-http-url.cpp b/tests/test-http-url.cpp
index 71b2f703..d574f1e2 100644
--- a/tests/test-http-url.cpp
+++ b/tests/test-http-url.cpp
@@ -3,7 +3,7 @@
 
 using namespace i2p::http;
 
-int main(int argc, char *argv[]) {
+int main() {
   std::map<std::string, std::string> params;
   URL *url;
 
diff --git a/tests/test-http-url_decode.cpp b/tests/test-http-url_decode.cpp
index 1c548e6f..f72b2c50 100644
--- a/tests/test-http-url_decode.cpp
+++ b/tests/test-http-url_decode.cpp
@@ -3,7 +3,7 @@
 
 using namespace i2p::http;
 
-int main(int argc, char *argv[]) {
+int main() {
   std::string in("/%D1%81%D1%82%D1%80%D0%B0%D0%BD%D0%B8%D1%86%D0%B0/");
   std::string out = UrlDecode(in);