diff --git a/starboard/nplb/posix_compliance/posix_socket_receive_test.cc b/starboard/nplb/posix_compliance/posix_socket_receive_test.cc
index 9ca368c31bb8..f8480612cb87 100644
--- a/starboard/nplb/posix_compliance/posix_socket_receive_test.cc
+++ b/starboard/nplb/posix_compliance/posix_socket_receive_test.cc
@@ -37,8 +37,7 @@ int Transfer(int receive_socket_fd,
                             size - send_total, kSendFlags);
       if (bytes_sent < 0) {
         if (errno != EINPROGRESS) {
-          // TODO: b/321999529, need errno
-          // return -1;
+          return -1;
         }
         bytes_sent = 0;
       }
@@ -51,8 +50,7 @@ int Transfer(int receive_socket_fd,
 
     if (bytes_received < 0) {
       if (errno != EINPROGRESS) {
-        // TODO: b/321999529, need errno
-        // return -1;
+        return -1;
       }
       bytes_received = 0;
     }
diff --git a/starboard/nplb/posix_compliance/posix_socket_recvfrom_test.cc b/starboard/nplb/posix_compliance/posix_socket_recvfrom_test.cc
index c14192951e53..eb4f1be4fc5a 100644
--- a/starboard/nplb/posix_compliance/posix_socket_recvfrom_test.cc
+++ b/starboard/nplb/posix_compliance/posix_socket_recvfrom_test.cc
@@ -37,8 +37,7 @@ int Transfer(int receive_socket_fd,
                               size - send_total, kSendFlags, NULL, 0);
       if (bytes_sent < 0) {
         if (errno != EINPROGRESS) {
-          // TODO: b/321999529, need errno
-          // return -1;
+          return -1;
         }
         bytes_sent = 0;
       }
@@ -51,8 +50,7 @@ int Transfer(int receive_socket_fd,
 
     if (bytes_received < 0) {
       if (errno != EINPROGRESS) {
-        // TODO: b/321999529, need errno
-        // return -1;
+        return -1;
       }
       bytes_received = 0;
     }
diff --git a/starboard/nplb/posix_compliance/posix_socket_send_test.cc b/starboard/nplb/posix_compliance/posix_socket_send_test.cc
index 668fbd239832..c86a326bb019 100644
--- a/starboard/nplb/posix_compliance/posix_socket_send_test.cc
+++ b/starboard/nplb/posix_compliance/posix_socket_send_test.cc
@@ -76,8 +76,9 @@ TEST(PosixSocketSendTest, RainyDayUnconnectedSocket) {
   ssize_t bytes_written = send(socket_fd, buf, sizeof(buf), kSendFlags);
   EXPECT_FALSE(bytes_written >= 0);
 
-  // TODO: check errno: EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET ||
-  // errno == EPIPE);
+  EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+              errno == ENOTCONN);
+  SB_DLOG(INFO) << "Failed to send, errno = " << errno;
 
   EXPECT_TRUE(close(socket_fd) == 0);
 }
@@ -109,8 +110,10 @@ TEST(PosixSocketSendTest, RainyDaySendToClosedSocket) {
   void* thread_result;
   EXPECT_TRUE(pthread_join(send_thread, &thread_result) == 0);
 
-  // TODO: errno: EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno
-  // == EPIPE);
+  EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+              errno == ENOTCONN // errno on Windows
+      || errno == EINPROGRESS // errno on Evergreen);
+  SB_DLOG(INFO) << "Failed to send, errno = " << errno;
 
   // Clean up the server socket.
   EXPECT_TRUE(close(server_socket_fd) == 0);
@@ -143,9 +146,9 @@ TEST(PosixSocketSendTest, RainyDaySendToSocketUntilBlocking) {
 
     if (result < 0) {
       // If we didn't get a socket, it should be pending.
-      // TODO: export errno
-      // EXPECT_TRUE(errno == EINPROGRESS || errno == EAGAIN || errno ==
-      // EWOULDBLOCK);
+      EXPECT_TRUE(errno == EINPROGRESS || errno == EAGAIN ||
+                  errno == EWOULDBLOCK);
+      SB_DLOG(INFO) << "Failed to send, errno = " << errno;
       break;
     }
 
@@ -195,9 +198,8 @@ TEST(PosixSocketSendTest, RainyDaySendToSocketConnectionReset) {
     result = send(client_socket_fd, buff, sizeof(buff), kSendFlags);
 
     if (result < 0) {
-      // TODO: errno:
-      // EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno ==
-      // EPIPE);
+      EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+                  errno == ECONNABORTED);
       SB_DLOG(INFO) << "Failed to send, errno = " << errno;
       break;
     }
diff --git a/starboard/nplb/posix_compliance/posix_socket_sendto_test.cc b/starboard/nplb/posix_compliance/posix_socket_sendto_test.cc
index 5405e5e0e281..376acce46bad 100644
--- a/starboard/nplb/posix_compliance/posix_socket_sendto_test.cc
+++ b/starboard/nplb/posix_compliance/posix_socket_sendto_test.cc
@@ -79,8 +79,9 @@ TEST(PosixSocketSendtoTest, RainyDayUnconnectedSocket) {
       sendto(socket_fd, buf, sizeof(buf), kSendFlags, NULL, 0);
   EXPECT_FALSE(bytes_written >= 0);
 
-  // TODO: check errno: EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET ||
-  // errno == EPIPE);
+  EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+              errno == ENOTCONN);
+  SB_DLOG(INFO) << "Failed to send, errno = " << errno;
 
   EXPECT_TRUE(close(socket_fd) == 0);
 }
@@ -112,8 +113,10 @@ TEST(PosixSocketSendtoTest, RainyDaySendToClosedSocket) {
   void* thread_result;
   EXPECT_TRUE(pthread_join(send_thread, &thread_result) == 0);
 
-  // TODO: errno: EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno
-  // == EPIPE);
+  EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+              errno == ENOTCONN // errno on Windows
+      || errno == EINPROGRESS // errno on Evergreen);
+  SB_DLOG(INFO) << "Failed to send, errno = " << errno;
 
   // Clean up the server socket.
   EXPECT_TRUE(close(server_socket_fd) == 0);
@@ -146,9 +149,9 @@ TEST(PosixSocketSendtoTest, RainyDaySendToSocketUntilBlocking) {
 
     if (result < 0) {
       // If we didn't get a socket, it should be pending.
-      // TODO: export errno
-      // EXPECT_TRUE(errno == EINPROGRESS || errno == EAGAIN || errno ==
-      // EWOULDBLOCK);
+      EXPECT_TRUE(errno == EINPROGRESS || errno == EAGAIN ||
+                  errno == EWOULDBLOCK);
+      SB_DLOG(INFO) << "Failed to send, errno = " << errno;
       break;
     }
 
@@ -194,9 +197,8 @@ TEST(PosixSocketSendtoTest, RainyDaySendToSocketConnectionReset) {
     result = sendto(client_socket_fd, buff, sizeof(buff), kSendFlags, NULL, 0);
 
     if (result < 0) {
-      // TODO: errno:
-      // EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno ==
-      // EPIPE);
+      EXPECT_TRUE(errno == ECONNRESET || errno == ENETRESET || errno == EPIPE ||
+                  errno == ECONNABORTED);
       SB_DLOG(INFO) << "Failed to send, errno = " << errno;
       break;
     }