diff --git a/folly/portability/PThread.cpp b/folly/portability/PThread.cpp
index 2891c4c..7c98975 100644
--- a/folly/portability/PThread.cpp
+++ b/folly/portability/PThread.cpp
@@ -30,6 +30,7 @@
 #include <mutex>
 #include <shared_mutex>
 #include <thread>
+#include <atomic>

 #include <folly/lang/Assume.h>
 #include <folly/portability/Windows.h>
