1 files changed, 12 insertions, 4 deletions

diff --git a/lib/libc/sys/fcntl.2 b/lib/libc/sys/fcntl.2
index 41184b3f5ede..e6ddee9cb38c 100644
--- a/lib/libc/sys/fcntl.2
+++ b/lib/libc/sys/fcntl.2
@@ -82,8 +82,12 @@ system calls.
 .El
 .It Dv F_GETFD
 Get the close-on-exec flag associated with the file descriptor
-.Fa fd .
-If the low-order bit of the returned value is 0,
+.Fa fd
+as
+.Dv FD_CLOEXEC .
+If the returned value ANDed with
+.Dv FD_CLOEXEC
+is 0,
 the file will remain open across
 .Fn exec ,
 otherwise the file will be closed upon execution of
@@ -93,9 +97,13 @@ is ignored).
 .It Dv F_SETFD
 Set the close-on-exec flag associated with
 .Fa fd
-to the low order bit of
+to
+.Fa arg ,
+where
 .Fa arg
-(0 or 1 as above).
+is either 0 or
+.Dv FD_CLOEXEC ,
+as described above.
 .It Dv F_GETFL
 Get descriptor status flags, as described below
 .Fa ( arg