diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4eb8d9ca898..221d8dfd6e0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2003-08-07  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+	PR c++/11712
+	* pa-hpux.h, pa-hpux10.h, pa-hpux11.h (TARGET_OS_CPP_BUILTINS): Define
+	__STDC_EXT__ when using C++ dialect.
+
 2003-08-07  J"orn Rennecke <joern.rennecke@superh.com>
 
 	* sh.c (calc_live_regs): If the return address pointer is live,
diff --git a/gcc/config/pa/pa-hpux.h b/gcc/config/pa/pa-hpux.h
index 5b99ee5aadc..9287924f7b7 100644
--- a/gcc/config/pa/pa-hpux.h
+++ b/gcc/config/pa/pa-hpux.h
@@ -28,6 +28,12 @@ Boston, MA 02111-1307, USA.  */
 #define SIZE_TYPE "unsigned int"
 #define PTRDIFF_TYPE "int"
 
+/* GCC always defines __STDC__.  HP C++ compilers don't define it.  This
+   causes trouble when sys/stdsyms.h is included.  As a work around,
+   we define __STDC_EXT__.  A similar situation exists with respect to
+   the definition of __cplusplus.  We define _INCLUDE_LONGLONG
+   to prevent nlist.h from defining __STDC_32_MODE__ (no longlong
+   support).  */
 #undef TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()				\
   do								\
@@ -46,6 +52,7 @@ Boston, MA 02111-1307, USA.  */
 	  {							\
 	    builtin_define ("_HPUX_SOURCE");			\
 	    builtin_define ("_INCLUDE_LONGLONG");		\
+	    builtin_define ("__STDC_EXT__");			\
 	  }							\
 	else if (!flag_iso)					\
 	  {							\
diff --git a/gcc/config/pa/pa-hpux10.h b/gcc/config/pa/pa-hpux10.h
index 78ac2afef0d..c6740635478 100644
--- a/gcc/config/pa/pa-hpux10.h
+++ b/gcc/config/pa/pa-hpux10.h
@@ -20,6 +20,12 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+/* GCC always defines __STDC__.  HP C++ compilers don't define it.  This
+   causes trouble when sys/stdsyms.h is included.  As a work around,
+   we define __STDC_EXT__.  A similar situation exists with respect to
+   the definition of __cplusplus.  We define _INCLUDE_LONGLONG
+   to prevent nlist.h from defining __STDC_32_MODE__ (no longlong
+   support).  */
 #undef TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()				\
   do								\
@@ -36,6 +42,7 @@ Boston, MA 02111-1307, USA.  */
 	  {							\
 	    builtin_define ("_HPUX_SOURCE");			\
 	    builtin_define ("_INCLUDE_LONGLONG");		\
+	    builtin_define ("__STDC_EXT__");			\
 	  }							\
 	else if (!flag_iso)					\
 	  {							\
diff --git a/gcc/config/pa/pa-hpux11.h b/gcc/config/pa/pa-hpux11.h
index 5a35ace408b..ebf3dc4ec33 100644
--- a/gcc/config/pa/pa-hpux11.h
+++ b/gcc/config/pa/pa-hpux11.h
@@ -18,6 +18,12 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+/* GCC always defines __STDC__.  HP C++ compilers don't define it.  This
+   causes trouble when sys/stdsyms.h is included.  As a work around,
+   we define __STDC_EXT__.  A similar situation exists with respect to
+   the definition of __cplusplus.  We define _INCLUDE_LONGLONG
+   to prevent nlist.h from defining __STDC_32_MODE__ (no longlong
+   support).  */
 #undef TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()				\
   do								\
@@ -34,6 +40,7 @@ Boston, MA 02111-1307, USA.  */
 	  {							\
 	    builtin_define ("_HPUX_SOURCE");			\
 	    builtin_define ("_INCLUDE_LONGLONG");		\
+	    builtin_define ("__STDC_EXT__");			\
 	  }							\
 	else							\
 	  {							\