diff --git a/dns.opcodes.js b/dns.opcodes.js
new file mode 100644
index 0000000..112108e
--- /dev/null
+++ b/dns.opcodes.js
@@ -0,0 +1,13 @@
+(function (exports) {
+'use strict';
+
+var opcodes = exports.DNS_OPCODES = {
+  QUERY:  0x00  //  0
+};
+
+// and in reverse
+Object.keys(opcodes).forEach(function (key) {
+  opcodes[opcodes[key]] = key;
+});
+
+}('undefined' !== typeof window ? window : exports));