1 files changed, 2 insertions, 2 deletions

diff --git a/src/libs/dutil/WixToolset.DUtil/strutil.cpp b/src/libs/dutil/WixToolset.DUtil/strutil.cpp
index 013c1b12..3c643879 100644
--- a/src/libs/dutil/WixToolset.DUtil/strutil.cpp
+++ b/src/libs/dutil/WixToolset.DUtil/strutil.cpp
@@ -2774,7 +2774,7 @@ don't remain in memory.
 
 ****************************************************************************/
 extern "C" DAPI_(HRESULT) StrSecureZeroString(
-    __in LPWSTR pwz
+    __in_z_opt LPWSTR pwz
     )
 {
     HRESULT hr = S_OK;
@@ -2798,7 +2798,7 @@ don't remain in memory, then frees the string.
 
 ****************************************************************************/
 extern "C" DAPI_(HRESULT) StrSecureZeroFreeString(
-    __in LPWSTR pwz
+    __in_z_opt LPWSTR pwz
     )
 {
     HRESULT hr = S_OK;