diff --git a/TargetGroup.cc b/TargetGroup.cc
index 317ecd8ae..175025f31 100644
--- a/TargetGroup.cc
+++ b/TargetGroup.cc
@@ -260,6 +260,10 @@ static NetBlock *parse_expr_without_netmask(const char *hostexp, int af) {
 
   sslen = sizeof(ss);
   if (resolve_numeric(hostexp, 0, &ss, &sslen, AF_INET6) == 0) {
+    if (af != AF_INET6) {
+      error("%s looks like an IPv6 target specification -- you have to use the -6 option.", hostexp);
+      return NULL;
+    }
     NetBlockIPv6Netmask *netblock_ipv6;
 
     netblock_ipv6 = new NetBlockIPv6Netmask();
diff --git a/targets.cc b/targets.cc
index 654ea779b..4a3926d44 100644
--- a/targets.cc
+++ b/targets.cc
@@ -395,20 +395,6 @@ int TargetGroup::get_next_host(struct sockaddr_storage *ss, size_t *sslen) {
     delete netblock_hostname;
   }
 
-  /* Check for proper address family. Give a specific error message for IPv6
-     specifications appearing in IPv4 mode. */
-  if (o.af() == AF_INET && dynamic_cast<NetBlockIPv6Netmask *>(this->netblock) != NULL) {
-    error("%s looks like an IPv6 target specification -- you have to use the -6 option.",
-      this->netblock->str().c_str());
-    return -1;
-  }
-  if ((o.af() == AF_INET && dynamic_cast<NetBlockIPv4Ranges *>(this->netblock) == NULL) ||
-      (o.af() == AF_INET6 && dynamic_cast<NetBlockIPv6Netmask *>(this->netblock) == NULL)) {
-    error("Address family mismatch in target specification \"%s\".",
-      this->netblock->str().c_str());
-    return -1;
-  }
-
   if (this->netblock->next(ss, sslen))
     return 0;
   else