diff --git a/man3/errno.3 b/man3/errno.3
index 6cbbafed5..794be7c7b 100644
--- a/man3/errno.3
+++ b/man3/errno.3
@@ -94,7 +94,7 @@ must have distinct values, with the exception of
 .B EAGAIN
 and
 .BR EWOULDBLOCK ,
-which may be the same.
+which may be the same. On Linux, these two always have the same value.
 .PP
 The error numbers that correspond to each symbolic name
 vary across UNIX systems,
@@ -240,8 +240,9 @@ Connection reset (POSIX.1-2001).
 Resource deadlock avoided (POSIX.1-2001).
 .TP
 .B EDEADLOCK
-Synonym for
+On most platforms, a synonym for
 .BR EDEADLK .
+On some (e.g. Linux mips, powerpc, sparc), it is a separate error code "File locking deadlock error".
 .TP
 .B EDESTADDRREQ
 Destination address required (POSIX.1-2001).