diff --git a/lib/mongo/repl_set_connection.rb b/lib/mongo/repl_set_connection.rb
index 8ce120a..5eea01d 100644
--- a/lib/mongo/repl_set_connection.rb
+++ b/lib/mongo/repl_set_connection.rb
@@ -89,6 +89,7 @@ module Mongo
 
       # Are we allowing reads from secondaries?
       @read_secondary = opts.fetch(:read_secondary, false)
+      @slave_okay = false
 
       setup(opts)
     end
diff --git a/test/db_test.rb b/test/db_test.rb
index 0a53759..3001001 100644
--- a/test/db_test.rb
+++ b/test/db_test.rb
@@ -123,6 +123,13 @@ class DBTest < Test::Unit::TestCase
     @@db.remove_user('spongebob')
   end
 
+  def test_authenticate_with_special_characters
+    assert @@db.add_user('foo:bar', '@foo')
+    assert @@db.authenticate('foo:bar', '@foo')
+    @@db.logout
+    @@db.remove_user('foo:bar')
+  end
+
   def test_authenticate_with_connection_uri
     @@db.add_user('spongebob', 'squarepants')
     assert Mongo::Connection.from_uri("mongodb://spongebob:squarepants@#{host_port}/#{@@db.name}")