There is no such option any more.
diff --git a/doc/install.texi b/doc/install.texi
index e32b9a7..78379a8 100644
--- a/doc/install.texi
+++ b/doc/install.texi
@@ -72,8 +72,6 @@
 not turn on netlink support.
 @item --enable-snmp
 Enable SNMP support.  By default, SNMP support is disabled.
-@item --enable-nssa
-Enable support for Not So Stubby Area (see RC3101) in ospfd.
 @item --enable-opaque-lsa
 Enable support for Opaque LSAs (RFC2370) in ospfd.
 @item --disable-ospfapi