diff --git a/bgpq4.8 b/bgpq4.8
index bd2aabb..2c282ee 100644
--- a/bgpq4.8
+++ b/bgpq4.8
@@ -40,7 +40,7 @@
 .Fl H Ar asn
 .Fl t
 .Oc
-.Op Fl 46ABbDdJjNnsXU
+.Op Fl 46ABbDdJjNnpsXU
 .Op Fl a Ar asn
 .Op Fl r Ar len
 .Op Fl R Ar len
@@ -111,6 +111,8 @@ extra match conditions for Juniper route-filters.
 generate config for Nokia SR OS MD-CLI (Cisco IOS by default)
 .It Fl N
 generate config for Nokia SR OS classic CLI (Cisco IOS by default).
+.It Fl p
+emit prefixes where the origin ASN is in the private ASN range (disabled by default).
 .It Fl r Ar len
 allow more specific routes starting with specified masklen too.
 .It Fl R Ar len
diff --git a/expander.c b/expander.c
index 9030091..2d37f6f 100644
--- a/expander.c
+++ b/expander.c
@@ -50,6 +50,7 @@
 
 int debug_expander = 0;
 int pipelining = 1;
+int expand_special_asn = 0;
 
 static inline int
 tentry_cmp(struct sx_tentry *a, struct sx_tentry *b)
@@ -195,7 +196,8 @@ bgpq_expander_add_as(struct bgpq_expander *b, char *as)
 		return 0;
 	}
 
-	if (asno >= 4200000000ul || (asno >= 64496 && asno <= 65551)) {
+	if (!expand_special_asn &&
+	    (asno >= 4200000000ul || (asno >= 64496 && asno <= 65551))) {
 		sx_report(SX_ERROR,"Invalid AS number: %u\n", asno);
 		return 0;
 	}
diff --git a/main.c b/main.c
index ad59652..c50cd34 100644
--- a/main.c
+++ b/main.c
@@ -45,12 +45,13 @@
 extern int debug_expander;
 extern int debug_aggregation;
 extern int pipelining;
+extern int expand_special_asn;
 
 static int
 usage(int ecode)
 {
 	printf("\nUsage: bgpq4 [-h host[:port]] [-S sources] [-E|G|H <num>"
-	    "|f <num>|t] [-46ABbdJjKNnwXz] [-R len] <OBJECTS> ... "
+	    "|f <num>|t] [-46ABbdJjKNnpwXz] [-R len] <OBJECTS> ... "
 	    "[EXCEPT <OBJECTS> ...]\n");
 	printf("\nVendor targets:\n");
 	printf(" no option : Cisco IOS Classic (default)\n");
@@ -197,7 +198,7 @@ main(int argc, char* argv[])
 		expander.sources=getenv("IRRD_SOURCES");
 
 	while ((c = getopt(argc, argv,
-	    "467a:AbBdDEeF:S:jJKf:l:L:m:M:NnW:r:R:G:H:tTh:UuwXsvz")) != EOF) {
+	    "467a:AbBdDEeF:S:jJKf:l:L:m:M:NnpW:r:R:G:H:tTh:UuwXsvz")) != EOF) {
 	switch (c) {
 	case '4':
 		/* do nothing, expander already configured for IPv4 */
@@ -393,6 +394,9 @@ main(int argc, char* argv[])
 			vendor_exclusive();
 		expander.vendor = V_NOKIA_MD;
 		break;
+	case 'p':
+		expand_special_asn = 1;
+		break;
 	case 't':
 		if (expander.generation)
 			exclusive();