diff --git a/lib/httpx/channel.rb b/lib/httpx/channel.rb
index 49d60d73..3af93ca7 100644
--- a/lib/httpx/channel.rb
+++ b/lib/httpx/channel.rb
@@ -61,7 +61,7 @@ module HTTPX
       @io = io
       @options = Options.new(options)
       @window_size = @options.window_size
-      @read_buffer = "".b
+      @read_buffer = Buffer.new(BUFFER_SIZE)
       @write_buffer = Buffer.new(BUFFER_SIZE)
       @pending = []
       @state = :idle
@@ -79,6 +79,17 @@ module HTTPX
         uri.scheme == @io.scheme
     end
 
+    def interests
+      return :w if @state == :idle
+      readable = !@read_buffer.full?
+      writable = !@write_buffer.empty?
+      if readable
+        writable ? :rw : :r
+      else
+        writable ? :w : :r
+      end
+    end
+
     def to_io
       case @state
       when :idle
@@ -134,7 +145,7 @@ module HTTPX
         throw(:close, self) unless siz
         return if siz.zero?
         log { "READ: #{siz} bytes..." }
-        parser << @read_buffer
+        parser << @read_buffer.to_s
       end
     end
 
diff --git a/lib/httpx/connection.rb b/lib/httpx/connection.rb
index 675fefcb..236dbeac 100644
--- a/lib/httpx/connection.rb
+++ b/lib/httpx/connection.rb
@@ -21,6 +21,7 @@ module HTTPX
         if (channel = monitor.value)
           consume(channel)
         end
+        monitor.interests = channel.interests
       end
     end
 
@@ -57,7 +58,7 @@ module HTTPX
     private
 
     def register_channel(channel)
-      monitor = @selector.register(channel, :rw)
+      monitor = @selector.register(channel, :w)
       monitor.value = channel
       @channels << channel
     end