diff --git a/lib/attribute.js b/lib/attribute.js
index 2792296..235cc05 100644
--- a/lib/attribute.js
+++ b/lib/attribute.js
@@ -4,7 +4,7 @@ const assert = require('assert')
 
 const asn1 = require('@ldapjs/asn1')
 
-const Protocol = require('./protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -96,8 +96,8 @@ Attribute.prototype.parse = function parse (ber) {
   ber.readSequence()
   this.type = ber.readString()
 
-  if (ber.peek() === Protocol.LBER_SET) {
-    if (ber.readSequence(Protocol.LBER_SET)) {
+  if (ber.peek() === Protocol.core.LBER_SET) {
+    if (ber.readSequence(Protocol.core.LBER_SET)) {
       const end = ber.offset + ber.length
       while (ber.offset < end) { this._vals.push(ber.readString(asn1.Ber.OctetString, true)) }
     }
@@ -111,7 +111,7 @@ Attribute.prototype.toBer = function toBer (ber) {
 
   ber.startSequence()
   ber.writeString(this.type)
-  ber.startSequence(Protocol.LBER_SET)
+  ber.startSequence(Protocol.core.LBER_SET)
   if (this._vals.length) {
     this._vals.forEach(function (b) {
       ber.writeByte(asn1.Ber.OctetString)
diff --git a/lib/change.js b/lib/change.js
index 6f45dbe..80cf83f 100644
--- a/lib/change.js
+++ b/lib/change.js
@@ -3,7 +3,6 @@
 const assert = require('assert-plus')
 
 const Attribute = require('./attribute')
-// var Protocol = require('./protocol')
 
 /// --- API
 
diff --git a/lib/client/client.js b/lib/client/client.js
index b48132e..55aa2af 100644
--- a/lib/client/client.js
+++ b/lib/client/client.js
@@ -20,7 +20,7 @@ const Change = require('../change')
 const Control = require('../controls/index').Control
 const { Control: LdapControl } = require('@ldapjs/controls')
 const SearchPager = require('./search_pager')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const dn = require('../dn')
 const errors = require('../errors')
 const filters = require('../filters')
@@ -601,7 +601,7 @@ Client.prototype.search = function search (base,
       baseObject: baseDN,
       scope: options.scope || 'base',
       filter: options.filter,
-      derefAliases: options.derefAliases || Protocol.NEVER_DEREF_ALIASES,
+      derefAliases: options.derefAliases || Protocol.search.NEVER_DEREF_ALIASES,
       sizeLimit: options.sizeLimit || 0,
       timeLimit: options.timeLimit || 10,
       typesOnly: options.typesOnly || false,
diff --git a/lib/client/search_pager.js b/lib/client/search_pager.js
index 6e7d498..81b68a0 100644
--- a/lib/client/search_pager.js
+++ b/lib/client/search_pager.js
@@ -7,7 +7,6 @@ const assert = require('assert-plus')
 
 // var dn = require('../dn')
 // var messages = require('../messages/index')
-// var Protocol = require('../protocol')
 const { PagedResultsControl } = require('@ldapjs/controls')
 
 const CorkedEmitter = require('../corked_emitter.js')
diff --git a/lib/filters/filter.js b/lib/filters/filter.js
index bfd193c..7327c6a 100644
--- a/lib/filters/filter.js
+++ b/lib/filters/filter.js
@@ -2,21 +2,21 @@
 
 // var assert = require('assert')
 
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
 const TYPES = {
-  and: Protocol.FILTER_AND,
-  or: Protocol.FILTER_OR,
-  not: Protocol.FILTER_NOT,
-  equal: Protocol.FILTER_EQUALITY,
-  substring: Protocol.FILTER_SUBSTRINGS,
-  ge: Protocol.FILTER_GE,
-  le: Protocol.FILTER_LE,
-  present: Protocol.FILTER_PRESENT,
-  approx: Protocol.FILTER_APPROX,
-  ext: Protocol.FILTER_EXT
+  and: Protocol.search.FILTER_AND,
+  or: Protocol.search.FILTER_OR,
+  not: Protocol.search.FILTER_NOT,
+  equal: Protocol.search.FILTER_EQUALITY,
+  substring: Protocol.search.FILTER_SUBSTRINGS,
+  ge: Protocol.search.FILTER_GE,
+  le: Protocol.search.FILTER_LE,
+  present: Protocol.search.FILTER_PRESENT,
+  approx: Protocol.search.FILTER_APPROX,
+  ext: Protocol.search.FILTER_EXT
 }
 
 /// --- API
diff --git a/lib/filters/index.js b/lib/filters/index.js
index 6fd8d52..7cbe9eb 100644
--- a/lib/filters/index.js
+++ b/lib/filters/index.js
@@ -6,7 +6,7 @@ const asn1 = require('@ldapjs/asn1')
 
 const parents = require('ldap-filter')
 
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 const Filter = require('./filter')
 const AndFilter = require('./and_filter')
@@ -71,53 +71,53 @@ function _parse (ber) {
 
   const type = ber.readSequence()
   switch (type) {
-    case Protocol.FILTER_AND:
+    case Protocol.search.FILTER_AND:
       f = new AndFilter()
       parseSet(f)
       break
 
-    case Protocol.FILTER_APPROX:
+    case Protocol.search.FILTER_APPROX:
       f = new ApproximateFilter()
       f.parse(ber)
       break
 
-    case Protocol.FILTER_EQUALITY:
+    case Protocol.search.FILTER_EQUALITY:
       f = new EqualityFilter()
       f.parse(ber)
       return f
 
-    case Protocol.FILTER_EXT:
+    case Protocol.search.FILTER_EXT:
       f = new ExtensibleFilter()
       f.parse(ber)
       return f
 
-    case Protocol.FILTER_GE:
+    case Protocol.search.FILTER_GE:
       f = new GreaterThanEqualsFilter()
       f.parse(ber)
       return f
 
-    case Protocol.FILTER_LE:
+    case Protocol.search.FILTER_LE:
       f = new LessThanEqualsFilter()
       f.parse(ber)
       return f
 
-    case Protocol.FILTER_NOT:
+    case Protocol.search.FILTER_NOT:
       f = new NotFilter({
         filter: _parse(ber)
       })
       break
 
-    case Protocol.FILTER_OR:
+    case Protocol.search.FILTER_OR:
       f = new OrFilter()
       parseSet(f)
       break
 
-    case Protocol.FILTER_PRESENT:
+    case Protocol.search.FILTER_PRESENT:
       f = new PresenceFilter()
       f.parse(ber)
       break
 
-    case Protocol.FILTER_SUBSTRINGS:
+    case Protocol.search.FILTER_SUBSTRINGS:
       f = new SubstringFilter()
       f.parse(ber)
       break
diff --git a/lib/index.js b/lib/index.js
index 13664db..e6941f6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -5,7 +5,7 @@ const logger = require('./logger')
 const client = require('./client')
 const Attribute = require('./attribute')
 const Change = require('./change')
-const Protocol = require('./protocol')
+const Protocol = require('@ldapjs/protocol')
 const Server = require('./server')
 
 const controls = require('./controls')
diff --git a/lib/messages/abandon_request.js b/lib/messages/abandon_request.js
index 184164c..0895f16 100644
--- a/lib/messages/abandon_request.js
+++ b/lib/messages/abandon_request.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -13,7 +13,7 @@ function AbandonRequest (options) {
   assert.object(options)
   assert.optionalNumber(options.abandonID)
 
-  options.protocolOp = Protocol.LDAP_REQ_ABANDON
+  options.protocolOp = Protocol.operations.LDAP_REQ_ABANDON
   LDAPMessage.call(this, options)
 
   this.abandonID = options.abandonID || 0
diff --git a/lib/messages/abandon_response.js b/lib/messages/abandon_response.js
index aa3fbc8..1659179 100644
--- a/lib/messages/abandon_response.js
+++ b/lib/messages/abandon_response.js
@@ -4,7 +4,6 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./result')
-// var Protocol = require('../protocol')
 
 /// --- API
 
diff --git a/lib/messages/add_request.js b/lib/messages/add_request.js
index 2677a01..cc8c56c 100644
--- a/lib/messages/add_request.js
+++ b/lib/messages/add_request.js
@@ -5,7 +5,7 @@ const util = require('util')
 
 const LDAPMessage = require('./message')
 const Attribute = require('../attribute')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const lassert = require('../assert')
 
 /// --- API
@@ -16,7 +16,7 @@ function AddRequest (options) {
   lassert.optionalStringDN(options.entry)
   lassert.optionalArrayOfAttribute(options.attributes)
 
-  options.protocolOp = Protocol.LDAP_REQ_ADD
+  options.protocolOp = Protocol.operations.LDAP_REQ_ADD
   LDAPMessage.call(this, options)
 
   this.entry = options.entry || null
diff --git a/lib/messages/add_response.js b/lib/messages/add_response.js
index 31265cd..3cfac98 100644
--- a/lib/messages/add_response.js
+++ b/lib/messages/add_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function AddResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_ADD
+  options.protocolOp = Protocol.operations.LDAP_RES_ADD
   LDAPResult.call(this, options)
 }
 util.inherits(AddResponse, LDAPResult)
diff --git a/lib/messages/bind_request.js b/lib/messages/bind_request.js
index eb33e8f..993e1d6 100644
--- a/lib/messages/bind_request.js
+++ b/lib/messages/bind_request.js
@@ -6,7 +6,7 @@ const util = require('util')
 const asn1 = require('@ldapjs/asn1')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
@@ -20,7 +20,7 @@ function BindRequest (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REQ_BIND
+  options.protocolOp = Protocol.operations.LDAP_REQ_BIND
   LDAPMessage.call(this, options)
 
   this.version = options.version || 0x03
diff --git a/lib/messages/bind_response.js b/lib/messages/bind_response.js
index de4f078..af51709 100644
--- a/lib/messages/bind_response.js
+++ b/lib/messages/bind_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function BindResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_BIND
+  options.protocolOp = Protocol.operations.LDAP_RES_BIND
   LDAPResult.call(this, options)
 }
 util.inherits(BindResponse, LDAPResult)
diff --git a/lib/messages/compare_request.js b/lib/messages/compare_request.js
index bd8c24f..b66ac89 100644
--- a/lib/messages/compare_request.js
+++ b/lib/messages/compare_request.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const lassert = require('../assert')
 
 /// --- API
@@ -16,7 +16,7 @@ function CompareRequest (options) {
   assert.optionalString(options.value)
   lassert.optionalStringDN(options.entry)
 
-  options.protocolOp = Protocol.LDAP_REQ_COMPARE
+  options.protocolOp = Protocol.operations.LDAP_REQ_COMPARE
   LDAPMessage.call(this, options)
 
   this.entry = options.entry || null
diff --git a/lib/messages/compare_response.js b/lib/messages/compare_response.js
index 5b75667..7852411 100644
--- a/lib/messages/compare_response.js
+++ b/lib/messages/compare_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function CompareResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_COMPARE
+  options.protocolOp = Protocol.operations.LDAP_RES_COMPARE
   LDAPResult.call(this, options)
 }
 util.inherits(CompareResponse, LDAPResult)
diff --git a/lib/messages/del_request.js b/lib/messages/del_request.js
index 678f213..b932c93 100644
--- a/lib/messages/del_request.js
+++ b/lib/messages/del_request.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const lassert = require('../assert')
 
 /// --- API
@@ -14,7 +14,7 @@ function DeleteRequest (options) {
   assert.object(options)
   lassert.optionalStringDN(options.entry)
 
-  options.protocolOp = Protocol.LDAP_REQ_DELETE
+  options.protocolOp = Protocol.operations.LDAP_REQ_DELETE
   LDAPMessage.call(this, options)
 
   this.entry = options.entry || null
diff --git a/lib/messages/del_response.js b/lib/messages/del_response.js
index 92d130f..3af01c5 100644
--- a/lib/messages/del_response.js
+++ b/lib/messages/del_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function DeleteResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_DELETE
+  options.protocolOp = Protocol.operations.LDAP_RES_DELETE
   LDAPResult.call(this, options)
 }
 util.inherits(DeleteResponse, LDAPResult)
diff --git a/lib/messages/ext_request.js b/lib/messages/ext_request.js
index a8d6c63..24459e8 100644
--- a/lib/messages/ext_request.js
+++ b/lib/messages/ext_request.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -18,7 +18,7 @@ function ExtendedRequest (options) {
     throw new TypeError('options.requestValue must be a buffer or a string')
   }
 
-  options.protocolOp = Protocol.LDAP_REQ_EXTENSION
+  options.protocolOp = Protocol.operations.LDAP_REQ_EXTENSION
   LDAPMessage.call(this, options)
 
   this.requestName = options.requestName || ''
diff --git a/lib/messages/ext_response.js b/lib/messages/ext_response.js
index 3f8f183..9e5d8df 100644
--- a/lib/messages/ext_response.js
+++ b/lib/messages/ext_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -17,7 +17,7 @@ function ExtendedResponse (options) {
   this.responseName = options.responseName || undefined
   this.responseValue = options.responseValue || undefined
 
-  options.protocolOp = Protocol.LDAP_REP_EXTENSION
+  options.protocolOp = Protocol.operations.LDAP_RES_EXTENSION
   LDAPResult.call(this, options)
 }
 util.inherits(ExtendedResponse, LDAPResult)
diff --git a/lib/messages/message.js b/lib/messages/message.js
index cbdf4ff..fecf143 100644
--- a/lib/messages/message.js
+++ b/lib/messages/message.js
@@ -7,7 +7,6 @@ const asn1 = require('@ldapjs/asn1')
 
 const logger = require('../logger')
 // var Control = require('../controls').Control
-// var Protocol = require('../protocol')
 
 /// --- Globals
 
diff --git a/lib/messages/moddn_request.js b/lib/messages/moddn_request.js
index 0f54823..7358718 100644
--- a/lib/messages/moddn_request.js
+++ b/lib/messages/moddn_request.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const dn = require('../dn')
 const lassert = require('../assert')
 
@@ -18,7 +18,7 @@ function ModifyDNRequest (options) {
   lassert.optionalDN(options.newRdn)
   lassert.optionalDN(options.newSuperior)
 
-  options.protocolOp = Protocol.LDAP_REQ_MODRDN
+  options.protocolOp = Protocol.operations.LDAP_REQ_MODRDN
   LDAPMessage.call(this, options)
 
   this.entry = options.entry || null
diff --git a/lib/messages/moddn_response.js b/lib/messages/moddn_response.js
index 99ecaae..ad93b49 100644
--- a/lib/messages/moddn_response.js
+++ b/lib/messages/moddn_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function ModifyDNResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_MODRDN
+  options.protocolOp = Protocol.operations.LDAP_RES_MODRDN
   LDAPResult.call(this, options)
 }
 util.inherits(ModifyDNResponse, LDAPResult)
diff --git a/lib/messages/modify_request.js b/lib/messages/modify_request.js
index 03da309..f724305 100644
--- a/lib/messages/modify_request.js
+++ b/lib/messages/modify_request.js
@@ -5,7 +5,7 @@ const util = require('util')
 
 const LDAPMessage = require('./message')
 const Change = require('../change')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const lassert = require('../assert')
 
 /// --- API
@@ -16,7 +16,7 @@ function ModifyRequest (options) {
   lassert.optionalStringDN(options.object)
   lassert.optionalArrayOfAttribute(options.attributes)
 
-  options.protocolOp = Protocol.LDAP_REQ_MODIFY
+  options.protocolOp = Protocol.operations.LDAP_REQ_MODIFY
   LDAPMessage.call(this, options)
 
   this.object = options.object || null
diff --git a/lib/messages/modify_response.js b/lib/messages/modify_response.js
index ba6fef0..78aaad4 100644
--- a/lib/messages/modify_response.js
+++ b/lib/messages/modify_response.js
@@ -4,7 +4,7 @@ const assert = require('assert-plus')
 const util = require('util')
 
 const LDAPResult = require('./result')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -12,7 +12,7 @@ function ModifyResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_MODIFY
+  options.protocolOp = Protocol.operations.LDAP_RES_MODIFY
   LDAPResult.call(this, options)
 }
 util.inherits(ModifyResponse, LDAPResult)
diff --git a/lib/messages/parser.js b/lib/messages/parser.js
index 04ac82c..170fc28 100644
--- a/lib/messages/parser.js
+++ b/lib/messages/parser.js
@@ -33,7 +33,7 @@ const UnbindRequest = require('./unbind_request')
 const LDAPResult = require('./result')
 // var Message = require('./message')
 
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
@@ -118,83 +118,83 @@ Parser.prototype.getMessage = function (ber) {
 
   let Message
   switch (type) {
-    case Protocol.LDAP_REQ_ABANDON:
+    case Protocol.operations.LDAP_REQ_ABANDON:
       Message = AbandonRequest
       break
 
-    case Protocol.LDAP_REQ_ADD:
+    case Protocol.operations.LDAP_REQ_ADD:
       Message = AddRequest
       break
 
-    case Protocol.LDAP_REP_ADD:
+    case Protocol.operations.LDAP_RES_ADD:
       Message = AddResponse
       break
 
-    case Protocol.LDAP_REQ_BIND:
+    case Protocol.operations.LDAP_REQ_BIND:
       Message = BindRequest
       break
 
-    case Protocol.LDAP_REP_BIND:
+    case Protocol.operations.LDAP_RES_BIND:
       Message = BindResponse
       break
 
-    case Protocol.LDAP_REQ_COMPARE:
+    case Protocol.operations.LDAP_REQ_COMPARE:
       Message = CompareRequest
       break
 
-    case Protocol.LDAP_REP_COMPARE:
+    case Protocol.operations.LDAP_RES_COMPARE:
       Message = CompareResponse
       break
 
-    case Protocol.LDAP_REQ_DELETE:
+    case Protocol.operations.LDAP_REQ_DELETE:
       Message = DeleteRequest
       break
 
-    case Protocol.LDAP_REP_DELETE:
+    case Protocol.operations.LDAP_RES_DELETE:
       Message = DeleteResponse
       break
 
-    case Protocol.LDAP_REQ_EXTENSION:
+    case Protocol.operations.LDAP_REQ_EXTENSION:
       Message = ExtendedRequest
       break
 
-    case Protocol.LDAP_REP_EXTENSION:
+    case Protocol.operations.LDAP_RES_EXTENSION:
       Message = ExtendedResponse
       break
 
-    case Protocol.LDAP_REQ_MODIFY:
+    case Protocol.operations.LDAP_REQ_MODIFY:
       Message = ModifyRequest
       break
 
-    case Protocol.LDAP_REP_MODIFY:
+    case Protocol.operations.LDAP_RES_MODIFY:
       Message = ModifyResponse
       break
 
-    case Protocol.LDAP_REQ_MODRDN:
+    case Protocol.operations.LDAP_REQ_MODRDN:
       Message = ModifyDNRequest
       break
 
-    case Protocol.LDAP_REP_MODRDN:
+    case Protocol.operations.LDAP_RES_MODRDN:
       Message = ModifyDNResponse
       break
 
-    case Protocol.LDAP_REQ_SEARCH:
+    case Protocol.operations.LDAP_REQ_SEARCH:
       Message = SearchRequest
       break
 
-    case Protocol.LDAP_REP_SEARCH_ENTRY:
+    case Protocol.operations.LDAP_RES_SEARCH_ENTRY:
       Message = SearchEntry
       break
 
-    case Protocol.LDAP_REP_SEARCH_REF:
+    case Protocol.operations.LDAP_RES_SEARCH_REF:
       Message = SearchReference
       break
 
-    case Protocol.LDAP_REP_SEARCH:
+    case Protocol.operations.LDAP_RES_SEARCH:
       Message = SearchResponse
       break
 
-    case Protocol.LDAP_REQ_UNBIND:
+    case Protocol.operations.LDAP_REQ_UNBIND:
       Message = UnbindRequest
       break
 
@@ -204,7 +204,7 @@ Parser.prototype.getMessage = function (ber) {
                         ' not supported'),
         new LDAPResult({
           messageID: messageID,
-          protocolOp: type || Protocol.LDAP_REP_EXTENSION
+          protocolOp: type || Protocol.operations.LDAP_RES_EXTENSION
         }))
 
       return false
diff --git a/lib/messages/result.js b/lib/messages/result.js
index 3ae8b56..53a00c5 100644
--- a/lib/messages/result.js
+++ b/lib/messages/result.js
@@ -7,7 +7,7 @@ const util = require('util')
 
 const dtrace = require('../dtrace')
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
@@ -81,7 +81,7 @@ LDAPResult.prototype._parse = function (ber) {
 
   const t = ber.peek()
 
-  if (t === Protocol.LDAP_REP_REFERRAL) {
+  if (t === Protocol.operations.LDAP_RES_REFERRAL) {
     const end = ber.offset + ber.length
     while (ber.offset < end) { this.referrals.push(ber.readString()) }
   }
@@ -97,7 +97,7 @@ LDAPResult.prototype._toBer = function (ber) {
   ber.writeString(this.errorMessage || '')
 
   if (this.referrals.length) {
-    ber.startSequence(Protocol.LDAP_REP_REFERRAL)
+    ber.startSequence(Protocol.operations.LDAP_RES_REFERRAL)
     ber.writeStringArray(this.referrals)
     ber.endSequence()
   }
diff --git a/lib/messages/search_entry.js b/lib/messages/search_entry.js
index 7d24dbf..1ba74d2 100644
--- a/lib/messages/search_entry.js
+++ b/lib/messages/search_entry.js
@@ -7,7 +7,7 @@ const util = require('util')
 
 const LDAPMessage = require('./message')
 const Attribute = require('../attribute')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const lassert = require('../assert')
 
 /// --- Globals
@@ -21,7 +21,7 @@ function SearchEntry (options) {
   assert.object(options)
   lassert.optionalStringDN(options.objectName)
 
-  options.protocolOp = Protocol.LDAP_REP_SEARCH_ENTRY
+  options.protocolOp = Protocol.operations.LDAP_RES_SEARCH_ENTRY
   LDAPMessage.call(this, options)
 
   this.objectName = options.objectName || null
diff --git a/lib/messages/search_reference.js b/lib/messages/search_reference.js
index 6c9bad2..e10351a 100644
--- a/lib/messages/search_reference.js
+++ b/lib/messages/search_reference.js
@@ -6,7 +6,7 @@ const util = require('util')
 // var asn1 = require('@ldapjs/asn1')
 
 const LDAPMessage = require('./message')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 const dn = require('../dn')
 const url = require('../url')
 
@@ -21,7 +21,7 @@ function SearchReference (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_SEARCH_REF
+  options.protocolOp = Protocol.operations.LDAP_RES_SEARCH_REF
   LDAPMessage.call(this, options)
 
   this.uris = options.uris || []
diff --git a/lib/messages/search_request.js b/lib/messages/search_request.js
index fb6c1b9..e8fd345 100644
--- a/lib/messages/search_request.js
+++ b/lib/messages/search_request.js
@@ -9,7 +9,7 @@ const LDAPMessage = require('./message')
 // var LDAPResult = require('./result')
 const dn = require('../dn')
 const filters = require('../filters')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
@@ -21,7 +21,7 @@ function SearchRequest (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REQ_SEARCH
+  options.protocolOp = Protocol.operations.LDAP_REQ_SEARCH
   LDAPMessage.call(this, options)
 
   if (options.baseObject !== undefined) {
@@ -30,7 +30,7 @@ function SearchRequest (options) {
     this.baseObject = dn.parse('')
   }
   this.scope = options.scope || 'base'
-  this.derefAliases = options.derefAliases || Protocol.NEVER_DEREF_ALIASES
+  this.derefAliases = options.derefAliases || Protocol.search.NEVER_DEREF_ALIASES
   this.sizeLimit = options.sizeLimit || 0
   this.timeLimit = options.timeLimit || 0
   this.typesOnly = options.typesOnly || false
@@ -50,9 +50,9 @@ Object.defineProperties(SearchRequest.prototype, {
   scope: {
     get: function getScope () {
       switch (this._scope) {
-        case Protocol.SCOPE_BASE_OBJECT: return 'base'
-        case Protocol.SCOPE_ONE_LEVEL: return 'one'
-        case Protocol.SCOPE_SUBTREE: return 'sub'
+        case Protocol.search.SCOPE_BASE_OBJECT: return 'base'
+        case Protocol.search.SCOPE_ONE_LEVEL: return 'one'
+        case Protocol.search.SCOPE_SUBTREE: return 'sub'
         default:
           throw new Error(this._scope + ' is an invalid search scope')
       }
@@ -61,13 +61,13 @@ Object.defineProperties(SearchRequest.prototype, {
       if (typeof (val) === 'string') {
         switch (val) {
           case 'base':
-            this._scope = Protocol.SCOPE_BASE_OBJECT
+            this._scope = Protocol.search.SCOPE_BASE_OBJECT
             break
           case 'one':
-            this._scope = Protocol.SCOPE_ONE_LEVEL
+            this._scope = Protocol.search.SCOPE_ONE_LEVEL
             break
           case 'sub':
-            this._scope = Protocol.SCOPE_SUBTREE
+            this._scope = Protocol.search.SCOPE_SUBTREE
             break
           default:
             throw new Error(val + ' is an invalid search scope')
diff --git a/lib/messages/search_response.js b/lib/messages/search_response.js
index 77edc7b..4b8f99f 100644
--- a/lib/messages/search_response.js
+++ b/lib/messages/search_response.js
@@ -10,7 +10,7 @@ const SearchReference = require('./search_reference')
 const dtrace = require('../dtrace')
 const parseDN = require('../dn').parse
 const parseURL = require('../url').parse
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- API
 
@@ -18,7 +18,7 @@ function SearchResponse (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REP_SEARCH
+  options.protocolOp = Protocol.operations.LDAP_RES_SEARCH
   LDAPResult.call(this, options)
 
   this.attributes = options.attributes ? options.attributes.slice() : []
diff --git a/lib/messages/unbind_request.js b/lib/messages/unbind_request.js
index 10326e2..37a2092 100644
--- a/lib/messages/unbind_request.js
+++ b/lib/messages/unbind_request.js
@@ -5,7 +5,7 @@ const util = require('util')
 
 const LDAPMessage = require('./message')
 const dn = require('../dn')
-const Protocol = require('../protocol')
+const Protocol = require('@ldapjs/protocol')
 
 /// --- Globals
 
@@ -18,7 +18,7 @@ function UnbindRequest (options) {
   options = options || {}
   assert.object(options)
 
-  options.protocolOp = Protocol.LDAP_REQ_UNBIND
+  options.protocolOp = Protocol.operations.LDAP_REQ_UNBIND
   LDAPMessage.call(this, options)
 }
 util.inherits(UnbindRequest, LDAPMessage)
diff --git a/lib/messages/unbind_response.js b/lib/messages/unbind_response.js
index 3317984..bf42f93 100644
--- a/lib/messages/unbind_response.js
+++ b/lib/messages/unbind_response.js
@@ -6,7 +6,6 @@ const util = require('util')
 const dtrace = require('../dtrace')
 
 const LDAPMessage = require('./result')
-// var Protocol = require('../protocol')
 
 /// --- API
 // Ok, so there's really no such thing as an unbind 'response', but to make
diff --git a/lib/protocol.js b/lib/protocol.js
deleted file mode 100644
index 5b7927d..0000000
--- a/lib/protocol.js
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright 2011 Mark Cavage, Inc.  All rights reserved.
-
-module.exports = {
-
-  // Misc
-  LDAP_VERSION_3: 0x03,
-  LBER_SET: 0x31,
-  LDAP_CONTROLS: 0xa0,
-
-  // Search
-  SCOPE_BASE_OBJECT: 0,
-  SCOPE_ONE_LEVEL: 1,
-  SCOPE_SUBTREE: 2,
-
-  NEVER_DEREF_ALIASES: 0,
-  DEREF_IN_SEARCHING: 1,
-  DEREF_BASE_OBJECT: 2,
-  DEREF_ALWAYS: 3,
-
-  FILTER_AND: 0xa0,
-  FILTER_OR: 0xa1,
-  FILTER_NOT: 0xa2,
-  FILTER_EQUALITY: 0xa3,
-  FILTER_SUBSTRINGS: 0xa4,
-  FILTER_GE: 0xa5,
-  FILTER_LE: 0xa6,
-  FILTER_PRESENT: 0x87,
-  FILTER_APPROX: 0xa8,
-  FILTER_EXT: 0xa9,
-
-  // Protocol Operations
-  LDAP_REQ_BIND: 0x60,
-  LDAP_REQ_UNBIND: 0x42,
-  LDAP_REQ_SEARCH: 0x63,
-  LDAP_REQ_MODIFY: 0x66,
-  LDAP_REQ_ADD: 0x68,
-  LDAP_REQ_DELETE: 0x4a,
-  LDAP_REQ_MODRDN: 0x6c,
-  LDAP_REQ_COMPARE: 0x6e,
-  LDAP_REQ_ABANDON: 0x50,
-  LDAP_REQ_EXTENSION: 0x77,
-
-  LDAP_REP_BIND: 0x61,
-  LDAP_REP_SEARCH_ENTRY: 0x64,
-  LDAP_REP_SEARCH_REF: 0x73,
-  LDAP_REP_SEARCH: 0x65,
-  LDAP_REP_MODIFY: 0x67,
-  LDAP_REP_ADD: 0x69,
-  LDAP_REP_DELETE: 0x6b,
-  LDAP_REP_MODRDN: 0x6d,
-  LDAP_REP_COMPARE: 0x6f,
-  LDAP_REP_EXTENSION: 0x78
-}
diff --git a/lib/server.js b/lib/server.js
index 3601227..4d09e0c 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -12,7 +12,7 @@ const VError = require('verror').VError
 const dn = require('./dn')
 const dtrace = require('./dtrace')
 const errors = require('./errors')
-const Protocol = require('./protocol')
+const Protocol = require('@ldapjs/protocol')
 
 const Parser = require('./messages').Parser
 const AbandonResponse = require('./messages/abandon_response')
@@ -71,34 +71,34 @@ function getResponse (req) {
   let Response
 
   switch (req.protocolOp) {
-    case Protocol.LDAP_REQ_BIND:
+    case Protocol.operations.LDAP_REQ_BIND:
       Response = BindResponse
       break
-    case Protocol.LDAP_REQ_ABANDON:
+    case Protocol.operations.LDAP_REQ_ABANDON:
       Response = AbandonResponse
       break
-    case Protocol.LDAP_REQ_ADD:
+    case Protocol.operations.LDAP_REQ_ADD:
       Response = AddResponse
       break
-    case Protocol.LDAP_REQ_COMPARE:
+    case Protocol.operations.LDAP_REQ_COMPARE:
       Response = CompareResponse
       break
-    case Protocol.LDAP_REQ_DELETE:
+    case Protocol.operations.LDAP_REQ_DELETE:
       Response = DeleteResponse
       break
-    case Protocol.LDAP_REQ_EXTENSION:
+    case Protocol.operations.LDAP_REQ_EXTENSION:
       Response = ExtendedResponse
       break
-    case Protocol.LDAP_REQ_MODIFY:
+    case Protocol.operations.LDAP_REQ_MODIFY:
       Response = ModifyResponse
       break
-    case Protocol.LDAP_REQ_MODRDN:
+    case Protocol.operations.LDAP_REQ_MODRDN:
       Response = ModifyDNResponse
       break
-    case Protocol.LDAP_REQ_SEARCH:
+    case Protocol.operations.LDAP_REQ_SEARCH:
       Response = SearchResponse
       break
-    case Protocol.LDAP_REQ_UNBIND:
+    case Protocol.operations.LDAP_REQ_UNBIND:
       Response = UnbindResponse
       break
     default:
@@ -170,44 +170,44 @@ function fireDTraceProbe (req, res) {
 
   let op
   switch (req.protocolOp) {
-    case Protocol.LDAP_REQ_ABANDON:
+    case Protocol.operations.LDAP_REQ_ABANDON:
       op = 'abandon'
       break
-    case Protocol.LDAP_REQ_ADD:
+    case Protocol.operations.LDAP_REQ_ADD:
       op = 'add'
       probeArgs.push(req.attributes.length)
       break
-    case Protocol.LDAP_REQ_BIND:
+    case Protocol.operations.LDAP_REQ_BIND:
       op = 'bind'
       break
-    case Protocol.LDAP_REQ_COMPARE:
+    case Protocol.operations.LDAP_REQ_COMPARE:
       op = 'compare'
       probeArgs.push(req.attribute)
       probeArgs.push(req.value)
       break
-    case Protocol.LDAP_REQ_DELETE:
+    case Protocol.operations.LDAP_REQ_DELETE:
       op = 'delete'
       break
-    case Protocol.LDAP_REQ_EXTENSION:
+    case Protocol.operations.LDAP_REQ_EXTENSION:
       op = 'exop'
       probeArgs.push(req.name)
       probeArgs.push(req.value)
       break
-    case Protocol.LDAP_REQ_MODIFY:
+    case Protocol.operations.LDAP_REQ_MODIFY:
       op = 'modify'
       probeArgs.push(req.changes.length)
       break
-    case Protocol.LDAP_REQ_MODRDN:
+    case Protocol.operations.LDAP_REQ_MODRDN:
       op = 'modifydn'
       probeArgs.push(req.newRdn.toString())
       probeArgs.push((req.newSuperior ? req.newSuperior.toString() : ''))
       break
-    case Protocol.LDAP_REQ_SEARCH:
+    case Protocol.operations.LDAP_REQ_SEARCH:
       op = 'search'
       probeArgs.push(req.scope)
       probeArgs.push(req.filter.toString())
       break
-    case Protocol.LDAP_REQ_UNBIND:
+    case Protocol.operations.LDAP_REQ_UNBIND:
       op = 'unbind'
       break
     default:
@@ -343,22 +343,22 @@ function Server (options) {
       // parse string DNs for routing/etc
       try {
         switch (req.protocolOp) {
-          case Protocol.LDAP_REQ_BIND:
+          case Protocol.operations.LDAP_REQ_BIND:
             req.name = dn.parse(req.name)
             break
-          case Protocol.LDAP_REQ_ADD:
-          case Protocol.LDAP_REQ_COMPARE:
-          case Protocol.LDAP_REQ_DELETE:
+          case Protocol.operations.LDAP_REQ_ADD:
+          case Protocol.operations.LDAP_REQ_COMPARE:
+          case Protocol.operations.LDAP_REQ_DELETE:
             req.entry = dn.parse(req.entry)
             break
-          case Protocol.LDAP_REQ_MODIFY:
+          case Protocol.operations.LDAP_REQ_MODIFY:
             req.object = dn.parse(req.object)
             break
-          case Protocol.LDAP_REQ_MODRDN:
+          case Protocol.operations.LDAP_REQ_MODRDN:
             req.entry = dn.parse(req.entry)
             // TODO: handle newRdn/Superior
             break
-          case Protocol.LDAP_REQ_SEARCH:
+          case Protocol.operations.LDAP_REQ_SEARCH:
             req.baseObject = dn.parse(req.baseObject)
             break
           default:
@@ -406,7 +406,7 @@ function Server (options) {
           const next = messageIIFE
           if (chain.handlers[i]) { return chain.handlers[i++].call(chain.backend, req, res, next) }
 
-          if (req.protocolOp === Protocol.LDAP_REQ_BIND && res.status === 0) {
+          if (req.protocolOp === Protocol.operations.LDAP_REQ_BIND && res.status === 0) {
             // 0 length == anonymous bind
             if (req.dn.length === 0 && req.credentials === '') {
               conn.ldap.bindDN = new DN([new dn.RDN({ cn: 'anonymous' })])
@@ -417,7 +417,7 @@ function Server (options) {
 
           // unbind clear bindDN for safety
           // conn should terminate on unbind (RFC4511 4.3)
-          if (req.protocolOp === Protocol.LDAP_REQ_UNBIND && res.status === 0) {
+          if (req.protocolOp === Protocol.operations.LDAP_REQ_UNBIND && res.status === 0) {
             conn.ldap.bindDN = new DN([new dn.RDN({ cn: 'anonymous' })])
           }
 
@@ -536,7 +536,7 @@ module.exports = Server
  */
 Server.prototype.add = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_ADD, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_ADD, name, args)
 }
 
 /**
@@ -551,7 +551,7 @@ Server.prototype.add = function (name) {
  */
 Server.prototype.bind = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_BIND, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_BIND, name, args)
 }
 
 /**
@@ -566,7 +566,7 @@ Server.prototype.bind = function (name) {
  */
 Server.prototype.compare = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_COMPARE, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_COMPARE, name, args)
 }
 
 /**
@@ -581,7 +581,7 @@ Server.prototype.compare = function (name) {
  */
 Server.prototype.del = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_DELETE, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_DELETE, name, args)
 }
 
 /**
@@ -596,7 +596,7 @@ Server.prototype.del = function (name) {
  */
 Server.prototype.exop = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_EXTENSION, name, args, true)
+  return this._mount(Protocol.operations.LDAP_REQ_EXTENSION, name, args, true)
 }
 
 /**
@@ -611,7 +611,7 @@ Server.prototype.exop = function (name) {
  */
 Server.prototype.modify = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_MODIFY, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_MODIFY, name, args)
 }
 
 /**
@@ -626,7 +626,7 @@ Server.prototype.modify = function (name) {
  */
 Server.prototype.modifyDN = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_MODRDN, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_MODRDN, name, args)
 }
 
 /**
@@ -641,7 +641,7 @@ Server.prototype.modifyDN = function (name) {
  */
 Server.prototype.search = function (name) {
   const args = Array.prototype.slice.call(arguments, 1)
-  return this._mount(Protocol.LDAP_REQ_SEARCH, name, args)
+  return this._mount(Protocol.operations.LDAP_REQ_SEARCH, name, args)
 }
 
 /**
@@ -655,7 +655,7 @@ Server.prototype.search = function (name) {
  */
 Server.prototype.unbind = function () {
   const args = Array.prototype.slice.call(arguments, 0)
-  return this._mount(Protocol.LDAP_REQ_UNBIND, 'unbind', args, true)
+  return this._mount(Protocol.operations.LDAP_REQ_UNBIND, 'unbind', args, true)
 }
 
 Server.prototype.use = function use () {
@@ -787,7 +787,7 @@ Server.prototype._getHandlerChain = function _getHandlerChain (req, res) {
   let route
 
   // check anonymous bind
-  if (req.protocolOp === Protocol.LDAP_REQ_BIND &&
+  if (req.protocolOp === Protocol.operations.LDAP_REQ_BIND &&
       req.dn.toString() === '' &&
       req.credentials === '') {
     return {
@@ -799,7 +799,7 @@ Server.prototype._getHandlerChain = function _getHandlerChain (req, res) {
   const op = '0x' + req.protocolOp.toString(16)
 
   // Special cases are exops, unbinds and abandons. Handle those first.
-  if (req.protocolOp === Protocol.LDAP_REQ_EXTENSION) {
+  if (req.protocolOp === Protocol.operations.LDAP_REQ_EXTENSION) {
     route = routes[req.requestName]
     if (route) {
       return {
@@ -812,7 +812,7 @@ Server.prototype._getHandlerChain = function _getHandlerChain (req, res) {
         handlers: [noExOpHandler]
       }
     }
-  } else if (req.protocolOp === Protocol.LDAP_REQ_UNBIND) {
+  } else if (req.protocolOp === Protocol.operations.LDAP_REQ_UNBIND) {
     route = routes.unbind
     if (route) {
       return {
@@ -825,7 +825,7 @@ Server.prototype._getHandlerChain = function _getHandlerChain (req, res) {
         handlers: [defaultNoOpHandler]
       }
     }
-  } else if (req.protocolOp === Protocol.LDAP_REQ_ABANDON) {
+  } else if (req.protocolOp === Protocol.operations.LDAP_REQ_ABANDON) {
     return {
       backend: self,
       handlers: [defaultNoOpHandler]
diff --git a/package.json b/package.json
index 921a1fc..edcdec7 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,7 @@
   "dependencies": {
     "@ldapjs/asn1": "^1.0.0",
     "@ldapjs/controls": "^1.0.0",
+    "@ldapjs/protocol": "^1.0.0",
     "abstract-logging": "^2.0.0",
     "assert-plus": "^1.0.0",
     "backoff": "^2.5.0",