diff --git a/src/xenia/base/threading.h b/src/xenia/base/threading.h
index 62fb5e815..bb447f282 100644
--- a/src/xenia/base/threading.h
+++ b/src/xenia/base/threading.h
@@ -22,6 +22,7 @@
 #include <thread>
 #include <utility>
 #include <vector>
+#include <functional>
 
 namespace xe {
 namespace threading {