diff --git a/net/http/test/client_function_test.cpp b/net/http/test/client_function_test.cpp
index 29151c0d..7af2d2df 100644
--- a/net/http/test/client_function_test.cpp
+++ b/net/http/test/client_function_test.cpp
@@ -84,11 +84,12 @@ TEST(http_client, get) {
     auto op2 = client->new_operation(Verb::GET, target);
     DEFER(delete op2);
     op2->req.headers.content_length(0);
-    client->call(op2);
+    int ret = client->call(op2);
+    GTEST_ASSERT_EQ(0, ret);
 
     char resp_body_buf[1024];
     EXPECT_EQ(sizeof(socket_buf), op2->resp.resource_size());
-    auto ret = op2->resp.read(resp_body_buf, sizeof(socket_buf));
+    ret = op2->resp.read(resp_body_buf, sizeof(socket_buf));
     EXPECT_EQ(sizeof(socket_buf), ret);
     resp_body_buf[sizeof(socket_buf) - 1] = '\0';
     LOG_DEBUG(resp_body_buf);
diff --git a/net/utils.cpp b/net/utils.cpp
index 28827d77..2e9d5c52 100644
--- a/net/utils.cpp
+++ b/net/utils.cpp
@@ -260,19 +260,30 @@ class DefaultResolver : public Resolver {
         : dnscache_(cache_ttl), resolve_timeout_(resolve_timeout) {}
     ~DefaultResolver() { dnscache_.clear(); }
 
-    IPAddr resolve(const char *host) override {
+    IPAddr resolve(const char *host, bool ipv6 = false) override {
         auto ctr = [&]() -> IPAddr * {
-            auto *ip = new IPAddr();
+            std::vector<IPAddr> addrs;
             photon::semaphore sem;
             std::thread([&]() {
-                *ip = gethostbyname(host);
+                int ret = gethostbyname(host, addrs);
+                if (ret < 0) {
+                    addrs.clear();
+                }
                 sem.signal(1);
             }).detach();
             auto ret = sem.wait(1, resolve_timeout_);
             if (ret < 0 && errno == ETIMEDOUT) {
                 LOG_WARN("Domain resolution for ` timeout!", host);
+                return new IPAddr;  // undefined addr
+            } else if (addrs.empty()) {
+                LOG_WARN("Domain resolution for ` failed", host);
+                return new IPAddr;  // undefined addr
             }
-            return ip;
+            for (auto& each : addrs) {
+                if ((each.is_ipv4() ^ !ipv6) == 0)
+                    return new IPAddr(each);
+            }
+            return new IPAddr;      // undefined addr
         };
         return *(dnscache_.borrow(host, ctr));
     }
diff --git a/net/utils.h b/net/utils.h
index 9420686e..bf9eaa2c 100644
--- a/net/utils.h
+++ b/net/utils.h
@@ -153,9 +153,9 @@ bool zerocopy_available();
  */
 class Resolver : public Object {
 public:
-    // When failed, IPAddr(0) should be returned.
+    // When failed, return an Undefined IPAddr
     // Normally dns servers return multiple ips in random order, choosing the first one should suffice.
-    virtual IPAddr resolve(const char* host) = 0;
+    virtual IPAddr resolve(const char* host, bool ipv6 = false) = 0;
     virtual void resolve(const char* host, Delegate<void, IPAddr> func) = 0;
     virtual void discard_cache(const char* host) = 0;  // discard current cache of host:ip
 };