diff --git a/man2/copy_file_range.2 b/man2/copy_file_range.2
index 820fa6c25..facb16ba7 100644
--- a/man2/copy_file_range.2
+++ b/man2/copy_file_range.2
@@ -116,6 +116,12 @@ argument is not 0.
 .B EIO
 A low-level I/O error occurred while copying.
 .TP
+.B EISDIR
+.I fd_in
+or
+.I fd_out
+refers to a directory.
+.TP
 .B ENOMEM
 Out of memory.
 .TP