diff --git a/src/unix/core.c b/src/unix/core.c
index d5992772..e5c9a4d9 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -603,14 +603,6 @@ void uv__io_init(uv__io_t* w, uv__io_cb cb, int fd) {
 }
 
 
-/* Note that uv__io_start() and uv__io_stop() can't simply remove the watcher
- * from the queue when the new event mask equals the old one. The event ports
- * backend operates exclusively in single-shot mode and needs to rearm all fds
- * before each call to port_getn(). It's up to the individual backends to
- * filter out superfluous event mask modifications.
- */
-
-
 void uv__io_start(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
   assert(0 == (events & ~(UV__POLLIN | UV__POLLOUT)));
   assert(0 != events);
@@ -620,6 +612,20 @@ void uv__io_start(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
   w->pevents |= events;
   maybe_resize(loop, w->fd + 1);
 
+#if !defined(__sun)
+  /* The event ports backend needs to rearm all file descriptors on each and
+   * every tick of the event loop but the other backends allow us to
+   * short-circuit here if the event mask is unchanged.
+   */
+  if (w->events == w->pevents) {
+    if (w->events == 0 && !ngx_queue_empty(&w->watcher_queue)) {
+      ngx_queue_remove(&w->watcher_queue);
+      ngx_queue_init(&w->watcher_queue);
+    }
+    return;
+  }
+#endif
+
   if (ngx_queue_empty(&w->watcher_queue))
     ngx_queue_insert_tail(&loop->watcher_queue, &w->watcher_queue);
 
diff --git a/src/unix/kqueue.c b/src/unix/kqueue.c
index fa090709..378903a6 100644
--- a/src/unix/kqueue.c
+++ b/src/unix/kqueue.c
@@ -84,12 +84,6 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
     assert(w->fd >= 0);
     assert(w->fd < (int) loop->nwatchers);
 
-    /* Filter out no-op changes. This is for compatibility with the event ports
-     * backend, see uv__io_start().
-     */
-    if (w->events == w->pevents)
-      continue;
-
     if ((w->events & UV__POLLIN) == 0 && (w->pevents & UV__POLLIN) != 0) {
       filter = EVFILT_READ;
       fflags = 0;
diff --git a/src/unix/linux-core.c b/src/unix/linux-core.c
index 7c01d780..e1a75150 100644
--- a/src/unix/linux-core.c
+++ b/src/unix/linux-core.c
@@ -140,12 +140,6 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
     assert(w->fd >= 0);
     assert(w->fd < (int) loop->nwatchers);
 
-    /* Filter out no-op changes. This is for compatibility with the event ports
-     * backend, see the comment in uv__io_start().
-     */
-    if (w->events == w->pevents)
-      continue;
-
     e.events = w->pevents;
     e.data = w->fd;