diff --git a/lib/nsq/discovery.rb b/lib/nsq/discovery.rb
index 2009b58..eba651d 100644
--- a/lib/nsq/discovery.rb
+++ b/lib/nsq/discovery.rb
@@ -70,7 +70,7 @@ def get_nsqds(lookupd, topic = nil)
       uri.query = "ts=#{Time.now.to_i}"
       if topic
         uri.path = '/lookup'
-        uri.query += "&topic=#{URI.escape(topic)}"
+        uri.query += "&topic=#{URI.encode_www_form_component(topic)}"
       else
         uri.path = '/nodes'
       end