diff --git a/src/amqproxy/client.cr b/src/amqproxy/client.cr
index cd4a856..400639b 100644
--- a/src/amqproxy/client.cr
+++ b/src/amqproxy/client.cr
@@ -26,23 +26,32 @@ module AMQProxy
 
     # Keep a buffer of publish frames
     # Only send to upstream when the full message is received
-    @next_publish : AMQ::Protocol::Frame::Basic::Publish?
-    @next_header : AMQ::Protocol::Frame::Header?
-    @next_bodies = Array(AMQ::Protocol::Frame::BytesBody).new
+    @publish_buffers = Hash(UInt16, PublishBuffer).new
+
+    private class PublishBuffer
+      getter publish : AMQ::Protocol::Frame::Basic::Publish
+      property! header : AMQ::Protocol::Frame::Header?
+      getter bodies = Array(AMQ::Protocol::Frame::BytesBody).new
+
+      def initialize(@publish)
+      end
+
+      def full?
+        header.body_size == @bodies.sum &.body_size
+      end
+    end
 
     private def finish_publish(channel)
-      next_publish = @next_publish.not_nil!("Missing Basic.Publish frame")
-      next_header = @next_header.not_nil!("Missing Header frame")
+      buffer = @publish_buffers[channel]
       if upstream_channel = @channel_map[channel]
-        upstream_channel.write(next_publish)
-        upstream_channel.write(next_header)
-        @next_bodies.each do |body|
+        upstream_channel.write(buffer.publish)
+        upstream_channel.write(buffer.header)
+        buffer.bodies.each do |body|
           upstream_channel.write(body)
         end
       end
     ensure
-      @next_publish = @next_header = nil
-      @next_bodies.clear
+      @publish_buffers.delete channel
     end
 
     # frames from enduser
@@ -69,16 +78,14 @@ module AMQProxy
           # Server closed channel, CloseOk reply to server is already sent
           @channel_map.delete(frame.channel)
         when AMQ::Protocol::Frame::Basic::Publish
-          @next_publish = frame
+          @publish_buffers[frame.channel] = PublishBuffer.new(frame)
         when AMQ::Protocol::Frame::Header
-          @next_header = frame
+          @publish_buffers[frame.channel].header = frame
           finish_publish(frame.channel) if frame.body_size.zero?
         when AMQ::Protocol::Frame::BytesBody
-          @next_bodies << frame
-          if @next_header.not_nil!("Missing Header frame").body_size ==
-               @next_bodies.sum &.body_size
-            finish_publish(frame.channel)
-          end
+          buffer = @publish_buffers[frame.channel]
+          buffer.bodies << frame
+          finish_publish(frame.channel) if buffer.full?
         when frame.channel.zero?
           Log.error { "Unexpected connection frame: #{frame}" }
           close_connection(540_u16, "NOT_IMPLEMENTED", frame)