diff --git a/indra/llcommon/llcoros.cpp b/indra/llcommon/llcoros.cpp
index 939c70b7eaf547a0a2b983a59d43eaa6cf772b01..37bcfc32423c4aaffe51a1aac50fe84d60783bd0 100644
--- a/indra/llcommon/llcoros.cpp
+++ b/indra/llcommon/llcoros.cpp
@@ -26,6 +26,8 @@
  * $/LicenseInfo$
  */
 
+#include "llwin32headers.h"
+
 // Precompiled header
 #include "linden_common.h"
 // associated header