diff --git a/man2/ioctl_ficlonerange.2 b/man2/ioctl_ficlonerange.2
index d1da3e6d3..c4715d042 100644
--- a/man2/ioctl_ficlonerange.2
+++ b/man2/ioctl_ficlonerange.2
@@ -59,6 +59,9 @@ into the file
 at offset
 .IR dest_offset ",
 provided that both are files.
+If
+.IR src_length
+is zero, the ioctl reflinks to the end of the source file.
 This information is conveyed in a structure of
 the following form:
 .in +4n