diff --git a/cddl/lib/libdtrace/ip.d b/cddl/lib/libdtrace/ip.d
--- a/cddl/lib/libdtrace/ip.d
+++ b/cddl/lib/libdtrace/ip.d
@@ -262,8 +262,8 @@
 
 #pragma D binding "1.5" translator
 translator ifinfo_t < struct ifnet *p > {
-	if_name =	p->if_xname;
-	if_local =	(p->if_flags & IFF_LOOPBACK) == 0 ? 0 : 1;
+	if_name =	p == NULL ? "<unknown>" : p->if_xname;
+	if_local =	p == NULL ? 0 : (p->if_flags & IFF_LOOPBACK) == 0 ? 0 : 1;
 	if_addr =	(uintptr_t)p;
 };