diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 48c7c7c5e2caf96646f4b481e6748bdca32584fd..98ee56c1f2707bdb9792d3dbbc0b81f70b59680a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2003-06-17  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
+
+	* system.h (ANSI_PROTOTYPES, PTR_CONST, LONG_DOUBLE, VPARAMS,
+	VA_OPEN, VA_FIXEDARG, VA_CLOSE, VA_START): undef and poison these
+	libiberty macros.
+
 2003-06-17  Jason Merrill  <jason@redhat.com>
 
 	PR c++/10929
diff --git a/gcc/system.h b/gcc/system.h
index c8f38fb80346d24cc41911ce96d00711c0cd4f73..3214f7aa2dd8832511dbf9ebb174e9cc7111a93b 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -627,6 +627,17 @@ typedef char _Bool;
  #pragma GCC poison LANG_HOOKS_FUNCTION_MARK LANG_HOOKS_FUNCTION_FREE	\
 	LANG_HOOKS_MARK_TREE
 
+/* Libiberty macros that are no longer used in GCC.  */
+#undef ANSI_PROTOTYPES
+#undef PTR_CONST
+#undef LONG_DOUBLE
+#undef VPARAMS
+#undef VA_OPEN
+#undef VA_FIXEDARG
+#undef VA_CLOSE
+#undef VA_START
+ #pragma GCC poison ANSI_PROTOTYPES PTR_CONST LONG_DOUBLE VPARAMS VA_OPEN \
+  VA_FIXEDARG VA_CLOSE VA_START
 #endif /* IN_GCC */
 
 /* Note: not all uses of the `index' token (e.g. variable names and