diff --git a/rai/lib/work.hpp b/rai/lib/work.hpp
index ee98a407..ce3fb2a1 100644
--- a/rai/lib/work.hpp
+++ b/rai/lib/work.hpp
@@ -8,6 +8,7 @@
 #include <atomic>
 #include <memory>
 #include <thread>
+#include <condition_variable>
 
 namespace rai
 {