diff --git a/src/unix/core.c b/src/unix/core.c
index 4860ebbc..c2e7bd73 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -927,6 +927,11 @@ int uv__io_active(const uv__io_t* w, unsigned int events) {
 }
 
 
+int uv__fd_exists(uv_loop_t* loop, int fd) {
+  return (unsigned) fd < loop->nwatchers && loop->watchers[fd] != NULL;
+}
+
+
 int uv_getrusage(uv_rusage_t* rusage) {
   struct rusage usage;
 
diff --git a/src/unix/internal.h b/src/unix/internal.h
index 63e478fd..b0c5dcad 100644
--- a/src/unix/internal.h
+++ b/src/unix/internal.h
@@ -219,6 +219,7 @@ int uv__io_active(const uv__io_t* w, unsigned int events);
 int uv__io_check_fd(uv_loop_t* loop, int fd);
 void uv__io_poll(uv_loop_t* loop, int timeout); /* in milliseconds or -1 */
 int uv__io_fork(uv_loop_t* loop);
+int uv__fd_exists(uv_loop_t* loop, int fd);
 
 /* async */
 void uv__async_stop(uv_loop_t* loop);
diff --git a/src/unix/pipe.c b/src/unix/pipe.c
index 2c578dcb..91114db6 100644
--- a/src/unix/pipe.c
+++ b/src/unix/pipe.c
@@ -134,6 +134,9 @@ void uv__pipe_close(uv_pipe_t* handle) {
 int uv_pipe_open(uv_pipe_t* handle, uv_file fd) {
   int err;
 
+  if (uv__fd_exists(handle->loop, fd))
+    return UV_EEXIST;
+
   err = uv__nonblock(fd, 1);
   if (err)
     return err;
diff --git a/src/unix/poll.c b/src/unix/poll.c
index f3b0bf4e..3d5022b2 100644
--- a/src/unix/poll.c
+++ b/src/unix/poll.c
@@ -68,6 +68,9 @@ static void uv__poll_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
 int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd) {
   int err;
 
+  if (uv__fd_exists(loop, fd))
+    return UV_EEXIST;
+
   err = uv__io_check_fd(loop, fd);
   if (err)
     return err;
diff --git a/src/unix/tcp.c b/src/unix/tcp.c
index 9a46793f..27a2a613 100644
--- a/src/unix/tcp.c
+++ b/src/unix/tcp.c
@@ -263,6 +263,9 @@ int uv__tcp_connect(uv_connect_t* req,
 int uv_tcp_open(uv_tcp_t* handle, uv_os_sock_t sock) {
   int err;
 
+  if (uv__fd_exists(handle->loop, sock))
+    return UV_EEXIST;
+
   err = uv__nonblock(sock, 1);
   if (err)
     return err;
diff --git a/src/unix/udp.c b/src/unix/udp.c
index 74d613b6..15da047a 100644
--- a/src/unix/udp.c
+++ b/src/unix/udp.c
@@ -624,6 +624,9 @@ int uv_udp_open(uv_udp_t* handle, uv_os_sock_t sock) {
   if (handle->io_watcher.fd != -1)
     return UV_EBUSY;
 
+  if (uv__fd_exists(handle->loop, sock))
+    return UV_EEXIST;
+
   err = uv__nonblock(sock, 1);
   if (err)
     return err;
diff --git a/test/test-tcp-open.c b/test/test-tcp-open.c
index cb74c50e..f5d8f136 100644
--- a/test/test-tcp-open.c
+++ b/test/test-tcp-open.c
@@ -181,6 +181,20 @@ TEST_IMPL(tcp_open) {
                      connect_cb);
   ASSERT(r == 0);
 
+#ifndef _WIN32
+  {
+    uv_tcp_t client2;
+
+    r = uv_tcp_init(uv_default_loop(), &client2);
+    ASSERT(r == 0);
+
+    r = uv_tcp_open(&client2, sock);
+    ASSERT(r == UV_EEXIST);
+
+    uv_close((uv_handle_t*) &client2, NULL);
+  }
+#endif  /* !_WIN32 */
+
   uv_run(uv_default_loop(), UV_RUN_DEFAULT);
 
   ASSERT(shutdown_cb_called == 1);
diff --git a/test/test-udp-open.c b/test/test-udp-open.c
index e14b808e..ee04c99f 100644
--- a/test/test-udp-open.c
+++ b/test/test-udp-open.c
@@ -164,6 +164,20 @@ TEST_IMPL(udp_open) {
                   send_cb);
   ASSERT(r == 0);
 
+#ifndef _WIN32
+  {
+    uv_udp_t client2;
+
+    r = uv_udp_init(uv_default_loop(), &client2);
+    ASSERT(r == 0);
+
+    r = uv_udp_open(&client2, sock);
+    ASSERT(r == UV_EEXIST);
+
+    uv_close((uv_handle_t*) &client2, NULL);
+  }
+#endif  /* !_WIN32 */
+
   uv_run(uv_default_loop(), UV_RUN_DEFAULT);
 
   ASSERT(send_cb_called == 1);