diff --git a/contrib/async-test/test-server.cpp b/contrib/async-test/test-server.cpp
index b304e1b..9e696c9 100644
--- a/contrib/async-test/test-server.cpp
+++ b/contrib/async-test/test-server.cpp
@@ -28,7 +28,7 @@
 
  public:
   AggrAsyncHandler()
-    : eb_(NULL)
+    : eb_(nullptr)
     , pfact_(new TBinaryProtocolFactory())
   {
     leaf_ports_.push_back(8081);