diff --git a/lib/middleware.js b/lib/middleware.js
index 1fde5e16a..3c57a7e80 100644
--- a/lib/middleware.js
+++ b/lib/middleware.js
@@ -100,13 +100,12 @@ module.exports.log_and_etagify = function(req, res, next) {
 
 	var _send = res.send;
 	res.send = function(body) {
-		var error;
 		if (typeof(body) === 'string' || typeof(body) === 'object') {
 			res.header('Content-type', 'application/json');
 
 			if (typeof(body) === 'object' && body != null) {
 				if (body.error) {
-					error = body.error;
+					res._sinopia_error = body.error;
 				}
 				body = JSON.stringify(body, undefined, '\t');
 			}
@@ -116,8 +115,24 @@ module.exports.log_and_etagify = function(req, res, next) {
 			// send(null), send(204), etc.
 		}
 
+		res.send = _send;
+		res.send(body);
+	}
+
+	var bytesout = 0
+	var _write = res.write
+	res.write = function(buf) {
+		bytesout += buf.length
+		_write.apply(res, arguments)
+	}
+
+	var _end = res.end;
+	res.end = function(buf) {
+		if (buf) bytesout += buf.length
+		_end.apply(res, arguments)
+
 		var msg = '@{status}, user: @{user}, req: \'@{request.method} @{request.url}\'';
-		if (error) {
+		if (res._sinopia_error) {
 			msg += ', error: @{!error}';
 		} else {
 			msg += ', bytes: @{bytes.in}/@{bytes.out}';
@@ -127,15 +142,12 @@ module.exports.log_and_etagify = function(req, res, next) {
 			level: 35, // http
 			user: req.user,
 			status: res.statusCode,
-			error: error,
+			error: res._sinopia_error,
 			bytes: {
 				in: bytesin,
-				out: body.length,
+				out: bytesout,
 			}
 		}, msg);
-
-		res.send = _send;
-		res.send(body);
 	};
 	next();
 }