diff --git a/index.js b/index.js
index 72f9346..aeab452 100644
--- a/index.js
+++ b/index.js
@@ -1,5 +1,6 @@
 var types = require('./types')
 var rcodes = require('./rcodes')
+var opcodes = require('./opcodes')
 var ip = require('ip')
 var Buffer = require('safe-buffer').Buffer
 
@@ -128,7 +129,7 @@ header.decode = function (buf, offset) {
     type: flags & RESPONSE_FLAG ? 'response' : 'query',
     flags: flags & 32767,
     flag_qr: ((flags >> 15) & 0x1) === 1,
-    opcode: (flags >> 11) & 0xf,
+    opcode: opcodes.toString((flags >> 11) & 0xf),
     flag_auth: ((flags >> 10) & 0x1) === 1,
     flag_trunc: ((flags >> 9) & 0x1) === 1,
     flag_rd: ((flags >> 8) & 0x1) === 1,
diff --git a/opcodes.js b/opcodes.js
new file mode 100644
index 0000000..6b42db3
--- /dev/null
+++ b/opcodes.js
@@ -0,0 +1,48 @@
+/*
+ * Traditional DNS header OPCODEs (4-bits) defined by IANA in
+ * https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-5
+ */
+
+exports.toString = function (opcode) {
+  switch (opcode) {
+    case 0: return 'QUERY'
+    case 1: return 'IQUERY'
+    case 2: return 'STATUS'
+    case 3: return 'OPCODE_3'
+    case 4: return 'NOTIFY'
+    case 5: return 'UPDATE'
+    case 6: return 'OPCODE_6'
+    case 7: return 'OPCODE_7'
+    case 8: return 'OPCODE_8'
+    case 9: return 'OPCODE_9'
+    case 10: return 'OPCODE_10'
+    case 11: return 'OPCODE_11'
+    case 12: return 'OPCODE_12'
+    case 13: return 'OPCODE_13'
+    case 14: return 'OPCODE_14'
+    case 15: return 'OPCODE_15'
+  }
+  return 'OPCODE_' + opcode
+}
+
+exports.toOpcode = function (code) {
+  switch (code.toUpperCase()) {
+    case 'QUERY': return 0
+    case 'IQUERY': return 1
+    case 'STATUS': return 2
+    case 'OPCODE_3': return 3
+    case 'NOTIFY': return 4
+    case 'UPDATE': return 5
+    case 'OPCODE_6': return 6
+    case 'OPCODE_7': return 7
+    case 'OPCODE_8': return 8
+    case 'OPCODE_9': return 9
+    case 'OPCODE_10': return 10
+    case 'OPCODE_11': return 11
+    case 'OPCODE_12': return 12
+    case 'OPCODE_13': return 13
+    case 'OPCODE_14': return 14
+    case 'OPCODE_15': return 15
+  }
+  return 0
+}
diff --git a/package.json b/package.json
index a0acdc4..5f646d3 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,8 @@
   "files": [
     "index.js",
     "types.js",
-    "rcodes.js"
+    "rcodes.js",
+    "opcodes.js"
   ],
   "author": "Mathias Buus",
   "license": "MIT"
diff --git a/test.js b/test.js
index 996acad..fad0ddc 100644
--- a/test.js
+++ b/test.js
@@ -1,6 +1,7 @@
 var tape = require('tape')
 var packet = require('./')
 var rcodes = require('./rcodes')
+var opcodes = require('./opcodes')
 var Buffer = require('safe-buffer').Buffer
 
 tape('unknown', function (t) {
@@ -181,6 +182,12 @@ tape('rcode', function (t) {
     t.ok(errors[i] === rcodes.toString(code), 'rcode conversion from/to string matches: ' + rcodes.toString(code))
   }
 
+  const ops = ['QUERY', 'IQUERY', 'STATUS', 'OPCODE_3', 'NOTIFY', 'UPDATE', 'OPCODE_6', 'OPCODE_7', 'OPCODE_8', 'OPCODE_9', 'OPCODE_10', 'OPCODE_11', 'OPCODE_12', 'OPCODE_13', 'OPCODE_14', 'OPCODE_15']
+  for (i in ops) {
+    code = opcodes.toOpcode(ops[i])
+    t.ok(ops[i] === opcodes.toString(code), 'opcode conversion from/to string matches: ' + opcodes.toString(code))
+  }
+
   var buf = packet.encode({
     type: 'response',
     id: 45632,
@@ -193,7 +200,7 @@ tape('rcode', function (t) {
   })
   var val = packet.decode(buf)
   t.ok(val.type === 'response', 'decode type')
-  t.ok(val.opcode === 0, 'decode opcode')
+  t.ok(val.opcode === 'QUERY', 'decode opcode')
   t.ok(val.flag_qr === true, 'decode flag_auth')
   t.ok(val.flag_auth === true, 'decode flag_auth')
   t.ok(val.flag_trunc === false, 'decode flag_trunc')