diff --git a/indra/llcommon/llfasttimer.h b/indra/llcommon/llfasttimer.h
index cfe36fbf0aaf22cbacb1e2afd62424f6853ef77b..35d58235c333da5c951bf37d7e6a5d2715ed3eaa 100644
--- a/indra/llcommon/llfasttimer.h
+++ b/indra/llcommon/llfasttimer.h
@@ -33,6 +33,8 @@
 
 #if LL_WINDOWS
 #include <intrin.h>
+#else
+#include <x86intrin.h>
 #endif
 
 #define LL_FAST_TIMER_ON 1