diff --git a/reactos/base/system/userinit/livecd.c b/reactos/base/system/userinit/livecd.c
index 4d8b623caf9..7a004142664 100644
--- a/reactos/base/system/userinit/livecd.c
+++ b/reactos/base/system/userinit/livecd.c
@@ -402,7 +402,7 @@ LocaleDlgProc(
                 if (NewLcid == (LCID)CB_ERR)
                     break;
 
-                            SetThreadLocale(NewLcid);
+                            NtSetDefaultLocale(TRUE, NewLcid);
                             InitializeDefaultUserLocale(&NewLcid);
                         }
 
diff --git a/reactos/base/system/userinit/userinit.h b/reactos/base/system/userinit/userinit.h
index 60d431065e2..bb2c4bb96eb 100644
--- a/reactos/base/system/userinit/userinit.h
+++ b/reactos/base/system/userinit/userinit.h
@@ -21,6 +21,8 @@
 #include <winnls.h>
 #include <stdio.h>
 
+#include <ndk/exfuncs.h>
+
 #include <wine/debug.h>
 WINE_DEFAULT_DEBUG_CHANNEL(userinit);