1 files changed, 1 insertions, 1 deletions

diff --git a/src/libs/dutil/WixToolset.DUtil/logutil.cpp b/src/libs/dutil/WixToolset.DUtil/logutil.cpp
index ac68036a..bd21098c 100644
--- a/src/libs/dutil/WixToolset.DUtil/logutil.cpp
+++ b/src/libs/dutil/WixToolset.DUtil/logutil.cpp
@@ -87,7 +87,7 @@ extern "C" BOOL DAPI IsLogOpen()
 
 ********************************************************************/
 extern "C" void DAPI LogInitialize(
-    __in HMODULE hModule
+    __in_opt HMODULE hModule
     )
 {
     AssertSz(INVALID_HANDLE_VALUE == LogUtil_hLog && !LogUtil_sczLogPath, "LogInitialize() or LogOpen() - already called.");