diff --git a/mongoose.c b/mongoose.c
index c11daf8c..ddc506a9 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -2947,11 +2947,16 @@ static struct mg_connection *alloc_conn(struct mg_mgr *mgr, bool is_client,
 
 static long mg_sock_send(struct mg_connection *c, const void *buf, size_t len) {
   long n;
+#if defined(_WIN32)
+  // See #1338, #1382. On Windows, UDP send() can fail despite connected.
+  // Use sendto() instead. But not UNIX: e.g. on Mac we'll get EISCONN
   if (c->is_udp) {
     union usa usa;
     socklen_t slen = tousa(&c->peer, &usa);
     n = sendto(FD(c), (char *) buf, len, 0, &usa.sa, slen);
-  } else {
+  } else
+#endif
+  {
     n = send(FD(c), (char *) buf, len, MSG_NONBLOCKING);
   }
   return n == 0 ? -1 : n < 0 && mg_sock_would_block() ? 0 : n;
diff --git a/src/sock.c b/src/sock.c
index 11ea3426..6e816d2a 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -102,11 +102,16 @@ static struct mg_connection *alloc_conn(struct mg_mgr *mgr, bool is_client,
 
 static long mg_sock_send(struct mg_connection *c, const void *buf, size_t len) {
   long n;
+#if defined(_WIN32)
+  // See #1338, #1382. On Windows, UDP send() can fail despite connected.
+  // Use sendto() instead. But not UNIX: e.g. on Mac we'll get EISCONN
   if (c->is_udp) {
     union usa usa;
     socklen_t slen = tousa(&c->peer, &usa);
     n = sendto(FD(c), (char *) buf, len, 0, &usa.sa, slen);
-  } else {
+  } else
+#endif
+  {
     n = send(FD(c), (char *) buf, len, MSG_NONBLOCKING);
   }
   return n == 0 ? -1 : n < 0 && mg_sock_would_block() ? 0 : n;