diff --git a/lib/mongo/db.rb b/lib/mongo/db.rb
index b18ab04795..35c10f2cd0 100644
--- a/lib/mongo/db.rb
+++ b/lib/mongo/db.rb
@@ -589,6 +589,9 @@ def command(selector, opts={})
         end.join('; ')
         message << ').'
         code = result['code'] || result['assertionCode']
+        if result['writeErrors']
+          code = result['writeErrors'].first['code']
+        end
         raise ExecutionTimeout.new(message, code, result) if code == MAX_TIME_MS_CODE
         raise OperationFailure.new(message, code, result)
       end
diff --git a/test/functional/collection_test.rb b/test/functional/collection_test.rb
index bf4d18d2ae..5f0bba07aa 100644
--- a/test/functional/collection_test.rb
+++ b/test/functional/collection_test.rb
@@ -345,6 +345,18 @@ def test_update_write_command_with_error
     end
   end
 
+  def test_error_code
+    coll = @db['test-error-code']
+    coll.ensure_index(BSON::OrderedHash[:x, Mongo::ASCENDING], { :unique => true })
+    coll.save(:x => 2)
+    begin
+      coll.save(:x => 2)
+    rescue => ex
+      assert_not_nil ex.error_code
+    end
+    coll.drop
+  end
+
   def test_aggregation_cursor
     return unless @version >= '2.5.1'
     [10, 1000].each do |size|