diff --git a/lib/server.js b/lib/server.js
index f4610fc5f..c51e1e870 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -166,7 +166,7 @@ exports.start = function(cliOptions, done) {
       // clean up, close runner socket
       globalEmitter.once('run_complete', function(browsers, results) {
         resultReporter.removeAdapter(socketWrite);
-        socket.end(!results.exitCode && constant.EXIT_CODE_0);
+        socket.end(results.exitCode ? void 0 : constant.EXIT_CODE_0);
       });
     });