diff -up adns-1.4/src/general.c.rh514838 adns-1.4/src/general.c
--- adns-1.4/src/general.c.rh514838	2006-04-08 16:36:57.000000000 +0200
+++ adns-1.4/src/general.c	2009-08-06 13:55:06.752562767 +0200
@@ -267,6 +267,8 @@ static const struct sinfo {
   SINFO( nodata,              "No such data"                                 )
 };
 
+static const char *unknown_error_str = "unknown error code";
+
 static int si_compar(const void *key, const void *elem) {
   const adns_status *st= key;
   const struct sinfo *si= elem;
@@ -283,7 +285,7 @@ const char *adns_strerror(adns_status st
   const struct sinfo *si;
 
   si= findsinfo(st);
-  return si->string;
+  return (si == NULL) ? unknown_error_str : si->string;
 }
 
 const char *adns_errabbrev(adns_status st) {