diff --git a/dlls/msvcrt/msvcrt.h b/dlls/msvcrt/msvcrt.h
index 8f6ee08ef2a..669d8c29a98 100644
--- a/dlls/msvcrt/msvcrt.h
+++ b/dlls/msvcrt/msvcrt.h
@@ -31,6 +31,7 @@
 #include "windef.h"
 #include "winbase.h"
 #undef strncpy
+#undef wcsncpy
 
 extern BOOL sse2_supported DECLSPEC_HIDDEN;
 
diff --git a/dlls/msvcrt/tests/string.c b/dlls/msvcrt/tests/string.c
index b236301218f..6bf3b6e775d 100644
--- a/dlls/msvcrt/tests/string.c
+++ b/dlls/msvcrt/tests/string.c
@@ -33,6 +33,7 @@
 
 /* make it use a definition from string.h */
 #undef strncpy
+#undef wcsncpy
 #include "winbase.h"
 #include "winnls.h"
 #include "winuser.h"
diff --git a/dlls/ntdll/wcstring.c b/dlls/ntdll/wcstring.c
index eee856b21d0..a727e4defac 100644
--- a/dlls/ntdll/wcstring.c
+++ b/dlls/ntdll/wcstring.c
@@ -241,6 +241,7 @@ int __cdecl wcsncmp( LPCWSTR str1, LPCWSTR str2, size_t n )
 /*********************************************************************
  *           wcsncpy    (NTDLL.@)
  */
+#undef wcsncpy
 LPWSTR __cdecl wcsncpy( LPWSTR s1, LPCWSTR s2, size_t n )
 {
     WCHAR *ret = s1;
diff --git a/include/winbase.h b/include/winbase.h
index 5e35c31a3b7..2928385bde6 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -2888,9 +2888,11 @@ static inline LPSTR WINAPI lstrcatA( LPSTR dst, LPCSTR src )
     return strcat( dst, src );
 }
 
-/* strncpy doesn't do what you think, don't use it */
+/* strncpy/wcsncpy don't do what you think, don't use them */
 #undef strncpy
+#undef wcsncpy
 #define strncpy(d,s,n) error do_not_use_strncpy_use_lstrcpynA_or_memcpy_instead
+#define wcsncpy(d,s,n) error do_not_use_wcsncpy_use_lstrcpynW_or_memcpy_instead
 
 #endif /* !defined(__WINESRC__) || defined(WINE_NO_INLINE_STRING) */