diff --git a/libc/netdb/lib_dnsquery.c b/libc/netdb/lib_dnsquery.c
index 59196206b6..073ff7ee13 100644
--- a/libc/netdb/lib_dnsquery.c
+++ b/libc/netdb/lib_dnsquery.c
@@ -64,9 +64,14 @@
 
 #define MAX_RETRIES      8
 
-/* Buffer sizes */
+/* Buffer sizes
+ *
+ * The SEND_BUFFER_SIZE depends the configured DNS name size,
+ * sizeof(DNS query0 = Header (12 bytes) + DNS Name (Variable) +
+ *                     Query type (2 bytes) + Query Class (2 bytes)
+ */
 
-#define SEND_BUFFER_SIZE 64
+#define SEND_BUFFER_SIZE (32 + CONFIG_NETDB_DNSCLIENT_NAMESIZE)
 #define RECV_BUFFER_SIZE CONFIG_NETDB_DNSCLIENT_MAXRESPONSE
 
 /****************************************************************************