diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 496038e1e..385f9e4d0 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+Tue 24 Jul 2001 02:28:00 PM  Trevor Forbes <t4bs@hotmail.com>
+
+	* thread.cc (verifyable_object_isvalid): Don't validate
+	PTHREAD_MUTEX_INITIALIZER pointer as it will cause an exception
+	in IsBadWritePtr() when running GDB.
+			
 Wed 25 Jul 2001 23:46:00  Corinna Vinschen <corinna@vinschen.de>
 
 	* localtime.c: Changed whole file to become C++ clean. Rename to
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 3c8f16e03..640c9756a 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -747,7 +747,7 @@ check_valid_pointer (void *pointer)
 int
 verifyable_object_isvalid (verifyable_object * object, long magic)
 {
-  if (!object)
+  if (!object || object == PTHREAD_MUTEX_INITIALIZER)
     return 0;
   if (check_valid_pointer (object))
     return 0;