diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 3a81a51ac..976a685e5 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+Sun Jul 16 20:23:21 2000  Christopher Faylor <cgf@cygnus.com>
+
+	* _cygwin_crt0_common.cc: Undef 'environ' or suffer compiler error.
+
 Sun Jul 16 16:03:00 2000  Christopher Faylor <cgf@cygnus.com>
 
 	* environ.cc: Use new definition of "environ" throughout.
diff --git a/winsup/cygwin/lib/_cygwin_crt0_common.cc b/winsup/cygwin/lib/_cygwin_crt0_common.cc
index 4ca6dd74e..9c74e623f 100644
--- a/winsup/cygwin/lib/_cygwin_crt0_common.cc
+++ b/winsup/cygwin/lib/_cygwin_crt0_common.cc
@@ -13,6 +13,8 @@ details. */
 #include <reent.h>
 #include <stdlib.h>
 
+#undef environ
+
 extern "C"
 {
 char **environ;