diff --git a/src/core/dns.c b/src/core/dns.c
index 8bce106c..eabe8721 100644
--- a/src/core/dns.c
+++ b/src/core/dns.c
@@ -616,7 +616,7 @@ dns_lookup(const char *name, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addr
   }
 #endif /* DNS_LOCAL_HOSTLIST */
 #ifdef DNS_LOOKUP_LOCAL_EXTERN
-  if (DNS_LOOKUP_LOCAL_EXTERN(name, addr, LWIP_DNS_ADDRTYPE_ARG_OR_ZERO(dns_addrtype))) {
+  if (DNS_LOOKUP_LOCAL_EXTERN(name, addr, LWIP_DNS_ADDRTYPE_ARG_OR_ZERO(dns_addrtype)) == ERR_OK) {
     return ERR_OK;
   }
 #endif /* DNS_LOOKUP_LOCAL_EXTERN */
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 9ff31a4c..e6af1e59 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -884,8 +884,8 @@
  *  byte order).
  *
  *  Instead, you can also use an external function:
- *  \#define DNS_LOOKUP_LOCAL_EXTERN(x) extern u32_t my_lookup_function(const char *name)
- *  that returns the IP address or INADDR_NONE if not found.
+ *  \#define DNS_LOOKUP_LOCAL_EXTERN(x) extern err_t my_lookup_function(const char *name, ip_addr_t *addr, u8_t dns_addrtype)
+ *  that looks up the IP address and returns ERR_OK if found (LWIP_DNS_ADDRTYPE_* is passed in dns_addrtype).
  */
 #ifndef DNS_LOCAL_HOSTLIST
 #define DNS_LOCAL_HOSTLIST              0