diff --git a/contrib/fb303/cpp/FacebookBase.cpp b/contrib/fb303/cpp/FacebookBase.cpp
index 3c56975..eb2e63c 100644
--- a/contrib/fb303/cpp/FacebookBase.cpp
+++ b/contrib/fb303/cpp/FacebookBase.cpp
@@ -24,7 +24,7 @@
 
 FacebookBase::FacebookBase(std::string name) :
   name_(name) {
-  aliveSince_ = (int64_t) time(NULL);
+  aliveSince_ = (int64_t) time(nullptr);
 }
 
 inline void FacebookBase::getName(std::string& _return) {