diff --git a/src/libCom/osi/os/WIN32/osdTime.cpp b/src/libCom/osi/os/WIN32/osdTime.cpp
index 0fa0039f2..b7d3ca71e 100644
--- a/src/libCom/osi/os/WIN32/osdTime.cpp
+++ b/src/libCom/osi/os/WIN32/osdTime.cpp
@@ -33,6 +33,7 @@
 #define epicsExportSharedSymbols
 #include "osiTime.h"
 #include "errlog.h"
+#include "epicsAssert.h"
 
 //
 // performance counter last value, ticks per sec,