diff --git a/indra/llcommon/llfasttimer.h b/indra/llcommon/llfasttimer.h
index 645bbb88ff49dde87d0eb93adda5e8fee37e21ff..7e3c411758d6ce85b89c43ee4781823498f72e6d 100644
--- a/indra/llcommon/llfasttimer.h
+++ b/indra/llcommon/llfasttimer.h
@@ -39,7 +39,9 @@
 #define TIME_FAST_TIMERS 0
 
 #if LL_WINDOWS
+#define _interlockedbittestandset _dummy_func
 #include <intrin.h>
+#undef _interlockedbittestandset
 
 #define LL_INLINE __forceinline
 // shift off lower 8 bits for lower resolution but longer term timing