diff --git a/lib/collection.js b/lib/collection.js
index 2ee6c0bbe1e..519f105a664 100644
--- a/lib/collection.js
+++ b/lib/collection.js
@@ -3237,6 +3237,9 @@ var writeConcern = function(target, db, col, options) {
     target.writeConcern = db.writeConcern;
   }
 
+  // NOTE: there is probably a much better place for this
+  if (db.s.options.retryWrites) target.retryWrites = true;
+
   return target;
 };
 
diff --git a/lib/db.js b/lib/db.js
index 99d24b3ba87..adaa886a76e 100644
--- a/lib/db.js
+++ b/lib/db.js
@@ -106,7 +106,8 @@ var legalOptionNames = [
   'promoteBuffers',
   'promoteLongs',
   'promoteValues',
-  'compression'
+  'compression',
+  'retryWrites'
 ];
 
 /**
diff --git a/lib/url_parser.js b/lib/url_parser.js
index 1412045faa1..484979177e5 100644
--- a/lib/url_parser.js
+++ b/lib/url_parser.js
@@ -3,7 +3,6 @@
 var ReadPreference = require('./read_preference'),
   parser = require('url'),
   f = require('util').format,
-  assign = require('./utils').assign,
   Logger = require('mongodb-core').Logger,
   dns = require('dns');
 
@@ -17,7 +16,6 @@ module.exports = function(url, options, callback) {
   }
 
   if (result.protocol === 'mongodb+srv:') {
-
     if (result.hostname.split('.').length < 3) {
       return callback(new Error('URI does not have hostname, domain name and tld'));
     }
@@ -552,6 +550,12 @@ function parseConnectionString(url, options) {
         compression.zlibCompressionLevel = zlibCompressionLevel;
         serverOptions.compression = compression;
         break;
+      case 'retryWrites':
+        dbOptions.retryWrites = value === 'true';
+        break;
+      case 'minSize':
+        dbOptions.minSize = parseInt(value, 10);
+        break;
       default:
         var logger = Logger('URL Parser');
         logger.warn(`${name} is not supported as a connection string option`);
@@ -577,7 +581,7 @@ function parseConnectionString(url, options) {
   }
 
   // make sure that user-provided options are applied with priority
-  dbOptions = assign(dbOptions, options);
+  dbOptions = Object.assign(dbOptions, options);
 
   // Add servers to result
   object.servers = servers;
diff --git a/package.json b/package.json
index 79a0a06a3cb..5fa01163cd3 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "official"
   ],
   "dependencies": {
-    "mongodb-core": "mongodb-js/mongodb-core#6510d7d3d82d84cc0811a853355deaa918b96941"
+    "mongodb-core": "mongodb-js/mongodb-core#0d74dfd32566d9ab8ebe9ae4b9af736e582e5533"
   },
   "devDependencies": {
     "betterbenchmarks": "^0.1.0",