diff --git a/reactos/subsystems/win/basesrv/nls.c b/reactos/subsystems/win/basesrv/nls.c
index 26de88cd9d8..88b42b8f47a 100644
--- a/reactos/subsystems/win/basesrv/nls.c
+++ b/reactos/subsystems/win/basesrv/nls.c
@@ -116,7 +116,7 @@ BaseSrvNLSInit(IN PBASE_STATIC_SERVER_DATA StaticData)
 
     /* Initialize the data with all F's */
     pNlsRegUserInfo = &StaticData->NlsUserInfo;
-    RtlFillMemory(&StaticData->NlsUserInfo, 0xFF, sizeof(StaticData->NlsUserInfo));
+    RtlFillMemory(&StaticData->NlsUserInfo, sizeof(StaticData->NlsUserInfo), 0xFF);
 
     /* Set empty LCID */
     pNlsRegUserInfo->UserLocaleId = 0;