diff --git a/reactos/lib/sdk/crt/locale/locale.c b/reactos/lib/sdk/crt/locale/locale.c
index 6d092f0eeb6..03f48cc9125 100644
--- a/reactos/lib/sdk/crt/locale/locale.c
+++ b/reactos/lib/sdk/crt/locale/locale.c
@@ -489,7 +489,7 @@ char *setlocale(int category, const char *locale)
 
   MSVCRT_current_lc_all_lcid = lcid;
 
-  snprintf(MSVCRT_current_lc_all,MAX_LOCALE_LENGTH,"%s_%s.%s",
+  _snprintf(MSVCRT_current_lc_all,MAX_LOCALE_LENGTH,"%s_%s.%s",
 	   lc.found_language,lc.found_country,lc.found_codepage);
 
   switch (category) {
diff --git a/reactos/lib/sdk/crt/string/wcs.c b/reactos/lib/sdk/crt/string/wcs.c
index d0708df588f..cfa253b7a85 100644
--- a/reactos/lib/sdk/crt/string/wcs.c
+++ b/reactos/lib/sdk/crt/string/wcs.c
@@ -48,6 +48,7 @@
 
 #undef sprintf
 #undef wsprintf
+#undef snprintf
 #undef vsnprintf
 #undef vprintf
 #undef vwprintf