diff --git a/src/core/dns.c b/src/core/dns.c
index 12b37e98..0c7901d2 100644
--- a/src/core/dns.c
+++ b/src/core/dns.c
@@ -110,11 +110,6 @@ static u16_t dns_txid;
 #define DNS_PORT_ALLOWED(port) ((port) >= 1024)
 #endif
 
-/** DNS maximum number of retries when asking for a name, before "timeout". */
-#ifndef DNS_MAX_RETRIES
-#define DNS_MAX_RETRIES           4
-#endif
-
 /** DNS resource record max. TTL (one week as default) */
 #ifndef DNS_MAX_TTL
 #define DNS_MAX_TTL               604800
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 430ef62e..f304e24c 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1085,6 +1085,11 @@
 #define DNS_MAX_SERVERS                 2
 #endif
 
+/** DNS maximum number of retries when asking for a name, before "timeout". */
+#ifndef DNS_MAX_RETRIES || defined __DOXYGEN__
+#define DNS_MAX_RETRIES           4
+#endif
+
 /** DNS do a name checking between the query and the response. */
 #if !defined DNS_DOES_NAME_CHECK || defined __DOXYGEN__
 #define DNS_DOES_NAME_CHECK             1