diff --git a/Include/pyport.h b/Include/pyport.h
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -699,6 +699,16 @@
 #       define HAVE_DECLSPEC_DLL
 #endif
 
+/*
+ * GCC visibility support, introduced in GCC 4.0. Only matters when
+ * compiling with gcc's -fvisibility=hidden argument.  This applies to all
+ * binaries and when embedding, not just libpython.so.  See
+ * http://gcc.gnu.org/wiki/Visibility for more information.
+ */
+#if defined(__GNUC__) && __GNUC__ >= 4
+#       define HAVE_ATTRIBUTE_VISIBILITY
+#endif
+
 /* only get special linkage if built as shared or platform is Cygwin */
 #if defined(Py_ENABLE_SHARED) || defined(__CYGWIN__)
 #       if defined(HAVE_DECLSPEC_DLL)
@@ -730,6 +740,16 @@
 #                       endif /* __cplusplus */
 #               endif /* Py_BUILD_CORE */
 #       endif /* HAVE_DECLSPEC */
+#elif defined(HAVE_ATTRIBUTE_VISIBILITY)
+#       define PyAPI_FUNC(RTYPE) __attribute__((visibility("default"))) RTYPE
+#       define PyAPI_DATA(RTYPE) extern __attribute__((visibility("default"))) RTYPE
+#       ifdef Py_BUILD_CORE
+#               define PyMODINIT_FUNC PyObject*
+#       elif defined(__cplusplus)
+#               define PyMODINIT_FUNC extern "C" __attribute__((visibility("default"))) PyObject*
+#       else /* __cplusplus */
+#               define PyMODINIT_FUNC __attribute__((visibility("default"))) PyObject*
+#       endif /* Py_BUILD_CORE */
 #endif /* Py_ENABLE_SHARED */
 
 /* If no external linkage macros defined by now, create defaults */
diff --git a/Modules/_ctypes/_ctypes_test.c b/Modules/_ctypes/_ctypes_test.c
--- a/Modules/_ctypes/_ctypes_test.c
+++ b/Modules/_ctypes/_ctypes_test.c
@@ -6,6 +6,8 @@
 
 #if defined(MS_WIN32) || defined(__CYGWIN__)
 #define EXPORT(x) __declspec(dllexport) x
+#elif defined(HAVE_ATTRIBUTE_VISIBILITY)
+#define EXPORT(x) __attribute__((visibility("default"))) x
 #else
 #define EXPORT(x) x
 #endif
diff --git a/Modules/_json.c b/Modules/_json.c
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -1756,7 +1756,7 @@
         NULL
 };
 
-PyObject*
+PyMODINIT_FUNC
 PyInit__json(void)
 {
     PyObject *m = PyModule_Create(&jsonmodule);
diff --git a/Modules/cjkcodecs/cjkcodecs.h b/Modules/cjkcodecs/cjkcodecs.h
--- a/Modules/cjkcodecs/cjkcodecs.h
+++ b/Modules/cjkcodecs/cjkcodecs.h
@@ -402,7 +402,7 @@
         NULL,                                                           \
         NULL                                                            \
     };                                                                  \
-    PyObject*                                                           \
+    PyMODINIT_FUNC                                                      \
     PyInit__codecs_##loc(void)                                          \
     {                                                                   \
         PyObject *m = PyModule_Create(&__module);                       \
diff --git a/Modules/nismodule.c b/Modules/nismodule.c
--- a/Modules/nismodule.c
+++ b/Modules/nismodule.c
@@ -456,8 +456,8 @@
     NULL
 };
 
-PyObject*
-PyInit_nis (void)
+PyMODINIT_FUNC
+PyInit_nis(void)
 {
     PyObject *m, *d;
     m = PyModule_Create(&nismodule);
diff --git a/Python/getargs.c b/Python/getargs.c
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -18,7 +18,6 @@
 int PyArg_VaParseTupleAndKeywords(PyObject *, PyObject *,
                                 const char *, char **, va_list);
 
-#ifdef HAVE_DECLSPEC_DLL
 /* Export functions */
 PyAPI_FUNC(int) _PyArg_Parse_SizeT(PyObject *, char *, ...);
 PyAPI_FUNC(int) _PyArg_ParseTuple_SizeT(PyObject *, char *, ...);
@@ -28,7 +27,6 @@
 PyAPI_FUNC(int) _PyArg_VaParse_SizeT(PyObject *, char *, va_list);
 PyAPI_FUNC(int) _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *, PyObject *,
                                               const char *, char **, va_list);
-#endif
 
 #define FLAG_COMPAT 1
 #define FLAG_SIZE_T 2