diff --git a/src/unix/core.c b/src/unix/core.c
index 1154fa25..b4cb948b 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -444,6 +444,10 @@ int uv__nonblock(int fd, int set) {
   if (r == -1)
     return -1;
 
+  /* Bail out now if already set/clear. */
+  if (!!(r & O_NONBLOCK) == !!set)
+    return 0;
+
   if (set)
     flags = r | O_NONBLOCK;
   else
@@ -468,6 +472,10 @@ int uv__cloexec(int fd, int set) {
   if (r == -1)
     return -1;
 
+  /* Bail out now if already set/clear. */
+  if (!!(r & FD_CLOEXEC) == !!set)
+    return 0;
+
   if (set)
     flags = r | FD_CLOEXEC;
   else