diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index a09e85f324d..6b657f900fc 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,7 @@
+2000-12-31  Alexandre Oliva  <aoliva@redhat.com>
+
+	* include/c_std/bits/std_cstdlib.h (mblen): Protect against macro.
+
 2000-12-23  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* src/Makefile.am (CSTD_INCLUDES): Change from CSHADOW_INCLUDES.
diff --git a/libstdc++-v3/include/c_std/bits/std_cstdlib.h b/libstdc++-v3/include/c_std/bits/std_cstdlib.h
index a43c1c58b90..0cd0359167f 100644
--- a/libstdc++-v3/include/c_std/bits/std_cstdlib.h
+++ b/libstdc++-v3/include/c_std/bits/std_cstdlib.h
@@ -85,6 +85,9 @@ namespace std
   extern "C" long int labs(long int); 
   extern "C" div_t div(int, int); 
   extern "C" ldiv_t ldiv(long int, long int); 
+#ifdef mblen
+#undef mblen
+#endif
   extern "C" int mblen(const char*, size_t); 
   extern "C" int mbtowc(wchar_t*, const char*, size_t); 
   extern "C" int wctomb(char*, wchar_t);