diff --git a/client/NetdClient.cpp b/client/NetdClient.cpp
index f025228..948b617 100644
--- a/client/NetdClient.cpp
+++ b/client/NetdClient.cpp
@@ -87,13 +87,13 @@
     }
     // Latency measurement does not include time of sending commands to Fwmark
     Stopwatch s;
-    int ret = libcConnect(sockfd, addr, addrlen);
+    const int ret = libcConnect(sockfd, addr, addrlen);
     // Save errno so it isn't clobbered by sending ON_CONNECT_COMPLETE
     const int connectErrno = errno;
     const unsigned latencyMs = lround(s.timeTaken());
     // Send an ON_CONNECT_COMPLETE command that includes sockaddr and connect latency for reporting
     if (shouldSetFwmark && FwmarkClient::shouldReportConnectComplete(addr->sa_family)) {
-        FwmarkConnectInfo connectInfo(latencyMs, addr);
+        FwmarkConnectInfo connectInfo(ret == 0 ? 0 : connectErrno, latencyMs, addr);
         // TODO: get the netId from the socket mark once we have continuous benchmark runs
         FwmarkCommand command = {FwmarkCommand::ON_CONNECT_COMPLETE, /* netId (ignored) */ 0,
                 /* uid (filled in by the server) */ 0};
diff --git a/include/FwmarkCommand.h b/include/FwmarkCommand.h
index a31b320..39ff233 100644
--- a/include/FwmarkCommand.h
+++ b/include/FwmarkCommand.h
@@ -23,6 +23,7 @@
 
 // Additional information sent with ON_CONNECT_COMPLETE command
 struct FwmarkConnectInfo {
+    int error;
     unsigned latencyMs;
     union {
         sockaddr s;
@@ -32,7 +33,8 @@
 
     FwmarkConnectInfo() {}
 
-    FwmarkConnectInfo(const unsigned latency, const sockaddr* saddr) {
+    FwmarkConnectInfo(const int connectErrno, const unsigned latency, const sockaddr* saddr) {
+        error = connectErrno;
         latencyMs = latency;
         if (saddr->sa_family == AF_INET) {
             addr.sin = *((struct sockaddr_in*) saddr);
diff --git a/server/FwmarkServer.cpp b/server/FwmarkServer.cpp
index b08f9f9..80df03f 100644
--- a/server/FwmarkServer.cpp
+++ b/server/FwmarkServer.cpp
@@ -165,7 +165,7 @@
         case FwmarkCommand::ON_CONNECT_COMPLETE: {
             // Called after a socket connect() completes.
             // This reports connect event including netId, destination IP address, destination port,
-            // uid and connect latency
+            // uid, connect latency, and connect errno if any.
 
             // Skip reporting if connect() happened on a UDP socket.
             int socketProto;
@@ -185,7 +185,8 @@
                         addrstr, sizeof(addrstr), portstr, sizeof(portstr),
                         NI_NUMERICHOST | NI_NUMERICSERV);
 
-                netdEventListener->onConnectEvent(fwmark.netId, connectInfo.latencyMs,
+                netdEventListener->onConnectEvent(fwmark.netId, connectInfo.error,
+                        connectInfo.latencyMs,
                         (ret == 0) ? String16(addrstr) : String16(""),
                         (ret == 0) ? strtoul(portstr, NULL, 10) : 0, client->getUid());
             }
diff --git a/server/binder/android/net/metrics/INetdEventListener.aidl b/server/binder/android/net/metrics/INetdEventListener.aidl
index 49a20f2..e966537 100644
--- a/server/binder/android/net/metrics/INetdEventListener.aidl
+++ b/server/binder/android/net/metrics/INetdEventListener.aidl
@@ -52,11 +52,12 @@
     /**
      * Logs a single connect library call.
      *
-     * @param netId the ID of the network the lookup was performed on.
-     * @param latencyMs the latency of the function call.
+     * @param netId the ID of the network the connect was performed on.
+     * @param error 0 if the connect call succeeded, otherwise errno if it failed.
+     * @param latencyMs the latency of the connect call.
      * @param ipAddr destination IP address.
      * @param port destination port number.
      * @param uid the UID of the application that performed the connection.
      */
-    void onConnectEvent(int netId, int latencyMs, String ipAddr, int port, int uid);
+    void onConnectEvent(int netId, int error, int latencyMs, String ipAddr, int port, int uid);
 }