Index: Modules/_ctypes/callproc.c
===================================================================
--- Modules/_ctypes/callproc.c	(revision 55100)
+++ Modules/_ctypes/callproc.c	(working copy)
@@ -1128,10 +1128,10 @@
 Free the handle of an executable previously loaded by LoadLibrary.\n";
 static PyObject *free_library(PyObject *self, PyObject *args)
 {
-	HMODULE hMod;
-	if (!PyArg_ParseTuple(args, "i:FreeLibrary", &hMod))
+	void *hMod;
+	if (!PyArg_ParseTuple(args, PY_VOIDP_T_CODE ":FreeLibrary", &hMod))
 		return NULL;
-	if (!FreeLibrary(hMod))
+	if (!FreeLibrary((HMODULE)hMod))
 		return PyErr_SetFromWindowsErr(GetLastError());
 	Py_INCREF(Py_None);
 	return Py_None;
@@ -1250,11 +1250,11 @@
 
 static PyObject *py_dl_close(PyObject *self, PyObject *args)
 {
-	int handle;
+	void *handle;
 
-	if (!PyArg_ParseTuple(args, "i:dlclose", &handle))
+	if (!PyArg_ParseTuple(args, PY_VOIDP_T_CODE ":dlclose", &handle))
 		return NULL;
-	if (dlclose((void*)handle)) {
+	if (dlclose(handle)) {
 		PyErr_SetString(PyExc_OSError,
 				       ctypes_dlerror());
 		return NULL;
@@ -1266,10 +1266,10 @@
 static PyObject *py_dl_sym(PyObject *self, PyObject *args)
 {
 	char *name;
-	int handle;
+	void *handle;
 	void *ptr;
 
-	if (!PyArg_ParseTuple(args, "is:dlsym", &handle, &name))
+	if (!PyArg_ParseTuple(args, PY_VOIDP_T_CODE "s:dlsym", &handle, &name))
 		return NULL;
 	ptr = ctypes_dlsym((void*)handle, name);
 	if (!ptr) {
@@ -1277,7 +1277,7 @@
 				       ctypes_dlerror());
 		return NULL;
 	}
-	return Py_BuildValue("i", ptr);
+	return PyLong_FromVoidPtr(ptr);
 }
 #endif
 
@@ -1289,12 +1289,12 @@
 static PyObject *
 call_function(PyObject *self, PyObject *args)
 {
-	int func;
+	void *func;
 	PyObject *arguments;
 	PyObject *result;
 
 	if (!PyArg_ParseTuple(args,
-			      "iO!",
+			      PY_VOIDP_T_CODE "O!",
 			      &func,
 			      &PyTuple_Type, &arguments))
 		return NULL;
@@ -1320,12 +1320,12 @@
 static PyObject *
 call_cdeclfunction(PyObject *self, PyObject *args)
 {
-	int func;
+	void *func;
 	PyObject *arguments;
 	PyObject *result;
 
 	if (!PyArg_ParseTuple(args,
-			      "iO!",
+			      PY_VOIDP_T_CODE "O!",
 			      &func,
 			      &PyTuple_Type, &arguments))
 		return NULL;
Index: Modules/_ctypes/ctypes.h
===================================================================
--- Modules/_ctypes/ctypes.h	(revision 55100)
+++ Modules/_ctypes/ctypes.h	(working copy)
@@ -6,6 +6,12 @@
 typedef int Py_ssize_t;
 #endif
 
+#if SIZEOF_VOID_P == SIZEOF_LONG
+#define PY_VOIDP_T_CODE "k"
+#elif SIZEOF_VOID_P == SIZEOF_LONG_LONG
+#define PY_VOIDP_T_CODE "K"
+#endif
+
 #ifndef MS_WIN32
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #define min(a, b) ((a) < (b) ? (a) : (b))