diff --git a/reactos/base/system/winlogon/screensaver.c b/reactos/base/system/winlogon/screensaver.c
index 635651b5a6c..17423e58f37 100644
--- a/reactos/base/system/winlogon/screensaver.c
+++ b/reactos/base/system/winlogon/screensaver.c
@@ -243,7 +243,7 @@ StartScreenSaver(
 	HKEY hKey = NULL;
 	WCHAR szApplicationName[MAX_PATH];
 	WCHAR szCommandLine[MAX_PATH + 3];
-	DWORD bufferSize = (sizeof(szApplicationName) / sizeof(WCHAR)) - 1;
+	DWORD bufferSize = sizeof(szApplicationName) - sizeof(WCHAR);
 	DWORD dwType;
 	STARTUPINFOW StartupInfo;
 	PROCESS_INFORMATION ProcessInformation;
@@ -280,7 +280,7 @@ StartScreenSaver(
 	if (bufferSize == 0)
 		goto cleanup;
 
-	szApplicationName[bufferSize] = 0; /* Terminate the string */
+	szApplicationName[bufferSize / sizeof(WCHAR)] = 0; /* Terminate the string */
 
 	if (wcslen(szApplicationName) == 0)
 		goto cleanup;