diff --git a/Include/abstract.h b/Include/abstract.h
index 357afe1..87b975d 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -288,9 +288,10 @@
 
        */
 
+       /* Declared elsewhere
+
      PyAPI_FUNC(int) PyCallable_Check(PyObject *o);
 
-       /*
 	 Determine if the object, o, is callable.  Return 1 if the
 	 object is callable and 0 otherwise.
 
diff --git a/Include/modsupport.h b/Include/modsupport.h
index 23d5d3a..761d960 100644
--- a/Include/modsupport.h
+++ b/Include/modsupport.h
@@ -24,7 +24,7 @@
 #endif
 
 PyAPI_FUNC(int) PyArg_Parse(PyObject *, const char *, ...);
-PyAPI_FUNC(int) PyArg_ParseTuple(PyObject *, const char *, ...);
+PyAPI_FUNC(int) PyArg_ParseTuple(PyObject *, const char *, ...) Py_FORMAT_PARSETUPLE(PyArg_ParseTuple, 2, 3);
 PyAPI_FUNC(int) PyArg_ParseTupleAndKeywords(PyObject *, PyObject *,
                                                   const char *, char **, ...);
 PyAPI_FUNC(int) PyArg_UnpackTuple(PyObject *, const char *, Py_ssize_t, Py_ssize_t, ...);
diff --git a/Include/pyport.h b/Include/pyport.h
index be6c51f..36d517c 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -3,6 +3,10 @@
 
 #include "pyconfig.h" /* include for defines */
 
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+
 /**************************************************************************
 Symbols and macros to supply platform-independent interfaces to basic
 C language & library operations whose spellings vary across platforms.
@@ -126,7 +130,7 @@
  * Py_ssize_t on the platform.
  */
 #ifndef PY_FORMAT_SIZE_T
-#   if SIZEOF_SIZE_T == SIZEOF_INT
+#   if SIZEOF_SIZE_T == SIZEOF_INT && !defined(__APPLE__)
 #       define PY_FORMAT_SIZE_T ""
 #   elif SIZEOF_SIZE_T == SIZEOF_LONG
 #       define PY_FORMAT_SIZE_T "l"
@@ -745,6 +749,15 @@
 #define Py_GCC_ATTRIBUTE(x) __attribute__(x)
 #endif
 
+/*
+ * Add PyArg_ParseTuple format where available.
+ */
+#ifdef HAVE_ATTRIBUTE_FORMAT_PARSETUPLE
+#define Py_FORMAT_PARSETUPLE(func,p1,p2) __attribute__((format(func,p1,p2)))
+#else
+#define Py_FORMAT_PARSETUPLE(func,p1,p2)
+#endif
+
 /* Eliminate end-of-loop code not reached warnings from SunPro C
  * when using do{...}while(0) macros
  */