diff --git a/lib/cmap/connection.js b/lib/cmap/connection.js
index 81925b96218..f8aad15dd1f 100644
--- a/lib/cmap/connection.js
+++ b/lib/cmap/connection.js
@@ -317,6 +317,7 @@ function write(command, options, callback) {
     promoteLongs: typeof options.promoteLongs === 'boolean' ? options.promoteLongs : true,
     promoteValues: typeof options.promoteValues === 'boolean' ? options.promoteValues : true,
     promoteBuffers: typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : false,
+    bsonRegExp: typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : false,
     raw: typeof options.raw === 'boolean' ? options.raw : false
   };
 
diff --git a/lib/collection.js b/lib/collection.js
index 09b8304b684..d55b2426104 100644
--- a/lib/collection.js
+++ b/lib/collection.js
@@ -120,6 +120,8 @@ function Collection(db, topology, dbName, name, pkFactory, options) {
     options == null || options.promoteBuffers == null
       ? db.s.options.promoteBuffers
       : options.promoteBuffers;
+  const bsonRegExp =
+    options == null || options.bsonRegExp == null ? db.s.options.bsonRegExp : options.bsonRegExp;
   const collectionHint = null;
 
   const namespace = new MongoDBNamespace(dbName, name);
@@ -156,6 +158,8 @@ function Collection(db, topology, dbName, name, pkFactory, options) {
     promoteValues: promoteValues,
     // promoteBuffers
     promoteBuffers: promoteBuffers,
+    // bsonRegExp
+    bsonRegExp: bsonRegExp,
     // internalHint
     internalHint: internalHint,
     // collectionHint
@@ -303,6 +307,7 @@ const DEPRECATED_FIND_OPTIONS = ['maxScan', 'fields', 'snapshot', 'oplogReplay']
  * @param {boolean} [options.promoteLongs=true] Promotes Long values to number if they fit inside the 53 bits resolution.
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {(ReadPreference|string)} [options.readPreference] The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST).
  * @param {boolean} [options.partial=false] Specify if the cursor should return partial results when querying against a sharded system
  * @param {number} [options.maxTimeMS] Number of milliseconds to wait before aborting the query.
@@ -451,6 +456,8 @@ Collection.prototype.find = deprecateOptions(
       newOptions.promoteValues = this.s.promoteValues;
     if (newOptions.promoteBuffers == null && typeof this.s.promoteBuffers === 'boolean')
       newOptions.promoteBuffers = this.s.promoteBuffers;
+    if (newOptions.bsonRegExp == null && typeof this.s.bsonRegExp === 'boolean')
+      newOptions.bsonRegExp = this.s.bsonRegExp;
 
     // Sort options
     if (findCommand.sort) {
@@ -1075,6 +1082,7 @@ Collection.prototype.save = deprecate(function(doc, options, callback) {
  * @param {boolean} [options.promoteLongs=true] Promotes Long values to number if they fit inside the 53 bits resolution.
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {(ReadPreference|string)} [options.readPreference] The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST).
  * @param {boolean} [options.partial=false] Specify if the cursor should return partial results when querying against a sharded system
  * @param {number} [options.maxTimeMS] Number of milliseconds to wait before aborting the query.
@@ -1899,6 +1907,7 @@ Collection.prototype.findAndRemove = deprecate(function(query, sort, options, ca
  * @param {boolean} [options.promoteLongs=true] Promotes Long values to number if they fit inside the 53 bits resolution.
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {object} [options.collation] Specify collation settings for operation. See {@link https://docs.mongodb.com/manual/reference/command/aggregate|aggregation documentation}.
  * @param {string} [options.comment] Add a comment to an aggregation command
  * @param {string|object} [options.hint] Add an index selection hint to an aggregation command
diff --git a/lib/core/connection/commands.js b/lib/core/connection/commands.js
index b24ff8481c4..b5446d93511 100644
--- a/lib/core/connection/commands.js
+++ b/lib/core/connection/commands.js
@@ -398,7 +398,12 @@ KillCursor.prototype.toBin = function() {
 };
 
 var Response = function(bson, message, msgHeader, msgBody, opts) {
-  opts = opts || { promoteLongs: true, promoteValues: true, promoteBuffers: false };
+  opts = opts || {
+    promoteLongs: true,
+    promoteValues: true,
+    promoteBuffers: false,
+    bsonRegExp: false
+  };
   this.parsed = false;
   this.raw = message;
   this.data = msgBody;
@@ -429,6 +434,7 @@ var Response = function(bson, message, msgHeader, msgBody, opts) {
   this.promoteLongs = typeof opts.promoteLongs === 'boolean' ? opts.promoteLongs : true;
   this.promoteValues = typeof opts.promoteValues === 'boolean' ? opts.promoteValues : true;
   this.promoteBuffers = typeof opts.promoteBuffers === 'boolean' ? opts.promoteBuffers : false;
+  this.bsonRegExp = typeof opts.bsonRegExp === 'boolean' ? opts.bsonRegExp : false;
 };
 
 Response.prototype.isParsed = function() {
@@ -449,13 +455,16 @@ Response.prototype.parse = function(options) {
     typeof options.promoteValues === 'boolean' ? options.promoteValues : this.opts.promoteValues;
   var promoteBuffers =
     typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : this.opts.promoteBuffers;
+  var bsonRegExp =
+    typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : this.opts.bsonRegExp;
   var bsonSize, _options;
 
   // Set up the options
   _options = {
     promoteLongs: promoteLongs,
     promoteValues: promoteValues,
-    promoteBuffers: promoteBuffers
+    promoteBuffers: promoteBuffers,
+    bsonRegExp: bsonRegExp
   };
 
   // Position within OP_REPLY at which documents start
diff --git a/lib/core/connection/connection.js b/lib/core/connection/connection.js
index c9d34960c8b..5870470c742 100644
--- a/lib/core/connection/connection.js
+++ b/lib/core/connection/connection.js
@@ -38,6 +38,7 @@ const DEBUG_FIELDS = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'checkServerIdentity'
 ];
 
@@ -73,6 +74,7 @@ class Connection extends EventEmitter {
    * @param {boolean} [options.promoteLongs] Convert Long values from the db into Numbers if they fit into 53 bits
    * @param {boolean} [options.promoteValues] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
    * @param {boolean} [options.promoteBuffers] Promotes Binary BSON values to native Node Buffers.
+   * @param {boolean} [options.bsonRegExp] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
    * @param {number} [options.maxBsonMessageSize=0x4000000] Largest possible size of a BSON message (for legacy purposes)
    */
   constructor(socket, options) {
@@ -117,7 +119,8 @@ class Connection extends EventEmitter {
     this.responseOptions = {
       promoteLongs: typeof options.promoteLongs === 'boolean' ? options.promoteLongs : true,
       promoteValues: typeof options.promoteValues === 'boolean' ? options.promoteValues : true,
-      promoteBuffers: typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : false
+      promoteBuffers: typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : false,
+      bsonRegExp: typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : false
     };
 
     // Flushing
diff --git a/lib/core/connection/msg.js b/lib/core/connection/msg.js
index e241c096af9..49744c328e9 100644
--- a/lib/core/connection/msg.js
+++ b/lib/core/connection/msg.js
@@ -139,7 +139,12 @@ Msg.getRequestId = function() {
 
 class BinMsg {
   constructor(bson, message, msgHeader, msgBody, opts) {
-    opts = opts || { promoteLongs: true, promoteValues: true, promoteBuffers: false };
+    opts = opts || {
+      promoteLongs: true,
+      promoteValues: true,
+      promoteBuffers: false,
+      bsonRegExp: false
+    };
     this.parsed = false;
     this.raw = message;
     this.data = msgBody;
@@ -161,6 +166,7 @@ class BinMsg {
     this.promoteLongs = typeof opts.promoteLongs === 'boolean' ? opts.promoteLongs : true;
     this.promoteValues = typeof opts.promoteValues === 'boolean' ? opts.promoteValues : true;
     this.promoteBuffers = typeof opts.promoteBuffers === 'boolean' ? opts.promoteBuffers : false;
+    this.bsonRegExp = typeof opts.bsonRegExp === 'boolean' ? opts.bsonRegExp : false;
 
     this.documents = [];
   }
@@ -186,12 +192,15 @@ class BinMsg {
       typeof options.promoteBuffers === 'boolean'
         ? options.promoteBuffers
         : this.opts.promoteBuffers;
+    const bsonRegExp =
+      typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : this.opts.bsonRegExp;
 
     // Set up the options
     const _options = {
       promoteLongs: promoteLongs,
       promoteValues: promoteValues,
-      promoteBuffers: promoteBuffers
+      promoteBuffers: promoteBuffers,
+      bsonRegExp: bsonRegExp
     };
 
     while (this.index < this.data.length) {
diff --git a/lib/core/connection/pool.js b/lib/core/connection/pool.js
index 491df52ceb6..369a66089e7 100644
--- a/lib/core/connection/pool.js
+++ b/lib/core/connection/pool.js
@@ -76,6 +76,7 @@ var _id = 0;
  * @param {boolean} [options.promoteLongs=true] Convert Long values from the db into Numbers if they fit into 53 bits
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {boolean} [options.domainsEnabled=false] Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.
  * @fires Pool#connect
  * @fires Pool#close
@@ -127,6 +128,7 @@ var Pool = function(topology, options) {
       promoteLongs: true,
       promoteValues: true,
       promoteBuffers: false,
+      bsonRegExp: false,
       // Reconnection options
       reconnect: true,
       reconnectInterval: 1000,
@@ -870,6 +872,7 @@ Pool.prototype.write = function(command, options, cb) {
     promoteLongs: true,
     promoteValues: true,
     promoteBuffers: false,
+    bsonRegExp: false,
     fullResult: false
   };
 
@@ -879,6 +882,7 @@ Pool.prototype.write = function(command, options, cb) {
     typeof options.promoteValues === 'boolean' ? options.promoteValues : true;
   operation.promoteBuffers =
     typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : false;
+  operation.bsonRegExp = typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : false;
   operation.raw = typeof options.raw === 'boolean' ? options.raw : false;
   operation.immediateRelease =
     typeof options.immediateRelease === 'boolean' ? options.immediateRelease : false;
diff --git a/lib/core/cursor.js b/lib/core/cursor.js
index 48b60d1a95b..7282a6b139b 100644
--- a/lib/core/cursor.js
+++ b/lib/core/cursor.js
@@ -146,6 +146,13 @@ class CoreCursor extends Readable {
       this.cursorState.promoteBuffers = options.promoteBuffers;
     }
 
+    // Add bsonRegExp to cursor state
+    if (typeof topologyOptions.bsonRegExp === 'boolean') {
+      this.cursorState.bsonRegExp = topologyOptions.bsonRegExp;
+    } else if (typeof options.bsonRegExp === 'boolean') {
+      this.cursorState.bsonRegExp = options.bsonRegExp;
+    }
+
     if (topologyOptions.reconnect) {
       this.cursorState.reconnect = topologyOptions.reconnect;
     }
diff --git a/lib/core/sdam/monitor.js b/lib/core/sdam/monitor.js
index 701fb59b28a..8a0876b746e 100644
--- a/lib/core/sdam/monitor.js
+++ b/lib/core/sdam/monitor.js
@@ -85,7 +85,8 @@ class Monitor extends EventEmitter {
         raw: false,
         promoteLongs: true,
         promoteValues: true,
-        promoteBuffers: true
+        promoteBuffers: true,
+        bsonRegExp: true
       }
     );
 
diff --git a/lib/core/sdam/server.js b/lib/core/sdam/server.js
index 7adb0dfb952..2cf0591d2c5 100644
--- a/lib/core/sdam/server.js
+++ b/lib/core/sdam/server.js
@@ -50,6 +50,7 @@ const DEBUG_FIELDS = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'servername'
 ];
 
diff --git a/lib/core/topologies/mongos.js b/lib/core/topologies/mongos.js
index b07d14ec691..27eb2375969 100644
--- a/lib/core/topologies/mongos.js
+++ b/lib/core/topologies/mongos.js
@@ -88,6 +88,7 @@ var handlers = ['connect', 'close', 'error', 'timeout', 'parseError'];
  * @param {boolean} [options.promoteLongs=true] Convert Long values from the db into Numbers if they fit into 53 bits
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {boolean} [options.domainsEnabled=false] Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.
  * @param {boolean} [options.monitorCommands=false] Enable command monitoring for this topology
  * @return {Mongos} A cursor instance
diff --git a/lib/core/topologies/replset.js b/lib/core/topologies/replset.js
index 03adc7cfe65..02c21486836 100644
--- a/lib/core/topologies/replset.js
+++ b/lib/core/topologies/replset.js
@@ -88,6 +88,7 @@ var handlers = ['connect', 'close', 'error', 'timeout', 'parseError'];
  * @param {boolean} [options.promoteLongs=true] Convert Long values from the db into Numbers if they fit into 53 bits
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {number} [options.pingInterval=5000] Ping interval to check the response time to the different servers
  * @param {number} [options.localThresholdMS=15] Cutoff latency point in MS for Replicaset member selection
  * @param {boolean} [options.domainsEnabled=false] Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.
diff --git a/lib/core/topologies/server.js b/lib/core/topologies/server.js
index 43bf7582059..ebc70870013 100644
--- a/lib/core/topologies/server.js
+++ b/lib/core/topologies/server.js
@@ -47,6 +47,7 @@ var debugFields = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'servername'
 ];
 
@@ -89,6 +90,7 @@ function topologyId(server) {
  * @param {boolean} [options.promoteLongs=true] Convert Long values from the db into Numbers if they fit into 53 bits
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {string} [options.appname=null] Application name, passed in on ismaster call and logged in mongod server logs. Maximum size 128 bytes.
  * @param {boolean} [options.domainsEnabled=false] Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit.
  * @param {boolean} [options.monitorCommands=false] Enable command monitoring for this topology
diff --git a/lib/core/wireprotocol/shared.js b/lib/core/wireprotocol/shared.js
index c586f057546..99c70a398e8 100644
--- a/lib/core/wireprotocol/shared.js
+++ b/lib/core/wireprotocol/shared.js
@@ -57,6 +57,7 @@ function applyCommonQueryOptions(queryOptions, options) {
     promoteLongs: typeof options.promoteLongs === 'boolean' ? options.promoteLongs : true,
     promoteValues: typeof options.promoteValues === 'boolean' ? options.promoteValues : true,
     promoteBuffers: typeof options.promoteBuffers === 'boolean' ? options.promoteBuffers : false,
+    bsonRegExp: typeof options.bsonRegExp === 'boolean' ? options.bsonRegExp : false,
     monitoring: typeof options.monitoring === 'boolean' ? options.monitoring : false,
     fullResult: typeof options.fullResult === 'boolean' ? options.fullResult : false
   });
diff --git a/lib/db.js b/lib/db.js
index eb70fa6d800..4d97ab87299 100644
--- a/lib/db.js
+++ b/lib/db.js
@@ -83,7 +83,6 @@ const legalOptionNames = [
   'bufferMaxEntries',
   'authSource',
   'ignoreUndefined',
-  'promoteLongs',
   'promiseLibrary',
   'readConcern',
   'retryMiliSeconds',
@@ -95,6 +94,7 @@ const legalOptionNames = [
   'promoteBuffers',
   'promoteLongs',
   'promoteValues',
+  'bsonRegExp',
   'compression',
   'retryWrites'
 ];
@@ -117,6 +117,7 @@ const legalOptionNames = [
  * @param {boolean} [options.promoteLongs=true] Promotes Long values to number if they fit inside the 53 bits resolution.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {number} [options.bufferMaxEntries=-1] Sets a cap on how many operations the driver will buffer up before giving up on getting a working connection, default is -1 which is unlimited.
  * @param {(ReadPreference|string)} [options.readPreference] The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST).
  * @param {object} [options.pkFactory] A primary key factory object for generation of custom _id keys.
@@ -323,6 +324,7 @@ Db.prototype.command = function(command, options, callback) {
  * @param {boolean} [options.promoteLongs=true] Promotes Long values to number if they fit inside the 53 bits resolution.
  * @param {boolean} [options.promoteValues=true] Promotes BSON values to native types where possible, set to false to only receive wrapper types.
  * @param {boolean} [options.promoteBuffers=false] Promotes Binary BSON values to native Node Buffers.
+ * @param {boolean} [options.bsonRegExp=false] By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @param {object} [options.collation] Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields).
  * @param {string} [options.comment] Add a comment to an aggregation command
  * @param {string|object} [options.hint] Add an index selection hint to an aggregation command
@@ -391,7 +393,8 @@ const COLLECTION_OPTION_KEYS = [
   'ignoreUndefined',
   'promoteValues',
   'promoteBuffers',
-  'promoteLongs'
+  'promoteLongs',
+  'bsonRegExp'
 ];
 
 /**
diff --git a/lib/mongo_client.js b/lib/mongo_client.js
index 7e11512bf15..5e668a681ee 100644
--- a/lib/mongo_client.js
+++ b/lib/mongo_client.js
@@ -144,6 +144,7 @@ const validOptions = require('./operations/connect').validOptions;
  * @property {boolean} [promoteValues] (**default**: true) Promotes BSON values to native types where possible, set to false to only receive wrapper types
  * @property {boolean} [promoteBuffers] (**default**: false) Promotes Binary BSON values to native Node Buffers
  * @property {boolean} [promoteLongs] (**default**: true) Promotes long values to number if they fit inside the 53 bits resolution
+ * * @param {boolean} [bsonRegExp] (**default**: false) By default, regex returned from MDB will be native to the language. Setting to true will ensure that a BSON.BSONRegExp object is returned.
  * @property {boolean} [domainsEnabled] (**default**: false) Enable the wrapping of the callback in the current domain, disabled by default to avoid perf hit
  * @property {object} [validateOptions] (**default**: false) Validate MongoClient passed in options for correctness
  * @property {string} [appname] (**default**: undefined) The name of the application that created this MongoClient instance. MongoDB 3.4 and newer will print this value in the server log upon establishing each connection. It is also recorded in the slow query log and profile collections
diff --git a/lib/operations/command.js b/lib/operations/command.js
index e65d3bbb493..769275f408e 100644
--- a/lib/operations/command.js
+++ b/lib/operations/command.js
@@ -22,6 +22,7 @@ const debugFields = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'bufferMaxEntries',
   'numberOfRetries',
   'retryMiliSeconds',
diff --git a/lib/operations/connect.js b/lib/operations/connect.js
index 4533d2847be..960497f7818 100644
--- a/lib/operations/connect.js
+++ b/lib/operations/connect.js
@@ -122,6 +122,7 @@ const validOptionNames = [
   'promoteValues',
   'promoteBuffers',
   'promoteLongs',
+  'bsonRegExp',
   'domainsEnabled',
   'checkServerIdentity',
   'validateOptions',
diff --git a/lib/operations/db_ops.js b/lib/operations/db_ops.js
index fb9c492da8d..785af776a02 100644
--- a/lib/operations/db_ops.js
+++ b/lib/operations/db_ops.js
@@ -24,6 +24,7 @@ const debugFields = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'bufferMaxEntries',
   'numberOfRetries',
   'retryMiliSeconds',
diff --git a/lib/topologies/mongos.js b/lib/topologies/mongos.js
index bf30d20ebef..784d3b4ef8a 100644
--- a/lib/topologies/mongos.js
+++ b/lib/topologies/mongos.js
@@ -54,6 +54,7 @@ var legalOptionNames = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'promiseLibrary',
   'monitorCommands'
 ];
diff --git a/lib/topologies/replset.js b/lib/topologies/replset.js
index 80701f5d3e3..90ca54362a8 100644
--- a/lib/topologies/replset.js
+++ b/lib/topologies/replset.js
@@ -60,6 +60,7 @@ var legalOptionNames = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'maxStalenessSeconds',
   'promiseLibrary',
   'minSize',
diff --git a/lib/topologies/server.js b/lib/topologies/server.js
index 0abaad3dba6..77507208d86 100644
--- a/lib/topologies/server.js
+++ b/lib/topologies/server.js
@@ -56,6 +56,7 @@ var legalOptionNames = [
   'promoteLongs',
   'promoteValues',
   'promoteBuffers',
+  'bsonRegExp',
   'compression',
   'promiseLibrary',
   'monitorCommands'
diff --git a/test/functional/unified-spec-runner/operations.ts b/test/functional/unified-spec-runner/operations.ts
index 4c83f44aa35..37982cd5de8 100644
--- a/test/functional/unified-spec-runner/operations.ts
+++ b/test/functional/unified-spec-runner/operations.ts
@@ -54,6 +54,8 @@ export interface BSONSerializeOptions extends Omit<SerializeOptions, 'index'> {
   promoteBuffers?: boolean;
   /** Promotes long values to number if they fit inside the 53 bits resolution */
   promoteLongs?: boolean;
+  /** Promotes RegExp to BSONRegExp object if enabled */
+  bsonRegExp?: boolean;
   /** Serialize functions on any object */
   serializeFunctions?: boolean;
   /** Specify if the BSON serializer should ignore undefined fields */
diff --git a/test/unit/bson_regex.test.js b/test/unit/bson_regex.test.js
new file mode 100644
index 00000000000..8a45bc14371
--- /dev/null
+++ b/test/unit/bson_regex.test.js
@@ -0,0 +1,43 @@
+'use strict';
+
+const expect = require('chai').expect;
+const BSONRegExp = require('bson').BSONRegExp;
+
+describe('BSONRegExp', () => {
+  describe('bsonRegExp option', () => {
+    // define option for tests to use
+    const option = { bsonRegExp: true };
+    for (const passOptionTo of ['client', 'db', 'collection', 'operation']) {
+      it(`should respond with BSONRegExp class with option passed to ${passOptionTo}`, function(done) {
+        const client = this.configuration.newClient(passOptionTo === 'client' ? option : undefined);
+        let collection;
+
+        client
+          .connect()
+          .then(() => {
+            const db = client.db('bson_regex_db', passOptionTo === 'db' ? option : undefined);
+            collection = db.collection(
+              'bson_regex_coll',
+              passOptionTo === 'collection' ? option : undefined
+            );
+          })
+          .then(() => collection.insertOne({ regex: new BSONRegExp('abc', 'imx') }))
+          .then(() =>
+            collection.findOne(
+              { regex: new BSONRegExp('abc', 'imx') },
+              passOptionTo === 'operation' ? option : undefined
+            )
+          )
+          .then(res =>
+            expect(res)
+              .has.property('regex')
+              .that.is.instanceOf(BSONRegExp)
+          )
+          .then(
+            () => client.close(done),
+            err => client.close(() => done(err))
+          );
+      });
+    }
+  });
+});