diff --git a/man2/mmap.2 b/man2/mmap.2
index 54d68cf87..17e7666c8 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -382,12 +382,14 @@ On error, the value
 .IR "(void\ *)\ \-1" )
 is returned, and
 .I errno
-is set appropriately.
+is set to indicate the cause of the error.
+
 On success,
 .BR munmap ()
-returns 0, on failure \-1, and
+returns 0.
+On failure, it returns \-1, and
 .I errno
-is set (probably to
+is set to indicate the cause of the error (probably to
 .BR EINVAL ).
 .SH ERRORS
 .TP