diff --git a/indra/llcommon/lltimer.cpp b/indra/llcommon/lltimer.cpp
index b250bc3e1c..466f98f9b2 100644
--- a/indra/llcommon/lltimer.cpp
+++ b/indra/llcommon/lltimer.cpp
@@ -30,6 +30,9 @@
 
 #include "u64.h"
 
+#include <chrono>
+#include <thread>
+
 #if LL_WINDOWS
 #	include "llwin32headerslean.h"
 #elif LL_LINUX || LL_DARWIN