diff --git a/man2/fsync.2 b/man2/fsync.2
index 76dcf96b1..655b09a30 100644
--- a/man2/fsync.2
+++ b/man2/fsync.2
@@ -122,7 +122,8 @@ An error occurred during synchronization.
 .TP
 .BR EROFS ", " EINVAL
 .I fd
-is bound to a special file which does not support synchronization.
+is bound to a special file (e.g., a pipe, FIFO, or socket)
+which does not support synchronization.
 .SH CONFORMING TO
 POSIX.1-2001, POSIX.1-2008, 4.3BSD.
 .SH AVAILABILITY