diff --git a/nmap.cc b/nmap.cc
index ba0c6d83c..21542fe99 100644
--- a/nmap.cc
+++ b/nmap.cc
@@ -1426,8 +1426,10 @@ void  apply_delayed_options() {
 
 
   if (o.osscan) {
-    o.reference_FPs = parse_fingerprint_reference_file("nmap-os-db");
-    o.os_labels_ipv6 = load_fp_matches();
+    if (o.af() == AF_INET)
+        o.reference_FPs = parse_fingerprint_reference_file("nmap-os-db");
+    else if (o.af() == AF_INET6)
+        o.os_labels_ipv6 = load_fp_matches();
   }
 
   // Must check and change this before validate_scan_lists