diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index ff35862..130e1c6 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -3996,8 +3996,8 @@ Struct_init(PyObject *self, PyObject *args, PyObject *kwds)
         return -1;
     }
     if (PyTuple_GET_SIZE(args)) {
-        int res = _init_pos_args(self, Py_TYPE(self),
-                                 args, kwds, 0);
+        Py_ssize_t res = _init_pos_args(self, Py_TYPE(self),
+                                        args, kwds, 0);
         if (res == -1)
             return -1;
         if (res < PyTuple_GET_SIZE(args)) {
diff --git a/Modules/_ctypes/libffi_msvc/prep_cif.c b/Modules/_ctypes/libffi_msvc/prep_cif.c
index 2650fa0..9dfa549 100644
--- a/Modules/_ctypes/libffi_msvc/prep_cif.c
+++ b/Modules/_ctypes/libffi_msvc/prep_cif.c
@@ -89,7 +89,7 @@ ffi_status ffi_prep_cif(/*@out@*/ /*@partial@*/ ffi_cif *cif,
 			/*@dependent@*/ /*@out@*/ /*@partial@*/ ffi_type *rtype, 
 			/*@dependent@*/ ffi_type **atypes)
 {
-  unsigned bytes = 0;
+  size_t bytes = 0;
   unsigned int i;
   ffi_type **ptr;
 
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 3061d8e..57178fb 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -219,8 +219,8 @@ typedef struct {
     PyObject* attrib;
 
     /* child elements */
-    int length; /* actual number of items */
-    int allocated; /* allocated items */
+    Py_ssize_t length; /* actual number of items */
+    Py_ssize_t allocated; /* allocated items */
 
     /* this either points to _children or to a malloced buffer */
     PyObject* *children;
@@ -337,9 +337,9 @@ element_new(PyObject* tag, PyObject* attrib)
 }
 
 LOCAL(int)
-element_resize(ElementObject* self, int extra)
+element_resize(ElementObject* self, Py_ssize_t extra)
 {
-    int size;
+    Py_ssize_t size;
     PyObject* *children;
 
     /* make sure self->children can hold the given number of extra
@@ -693,7 +693,7 @@ element_deepcopy(ElementObject* self, PyObject* args)
     }
 
     /* add object to memo dictionary (so deepcopy won't visit it again) */
-    id = PyLong_FromLong((Py_uintptr_t) self);
+    id = PyLong_FromVoidPtr(self);
     if (!id)
         goto error;
 
@@ -1219,7 +1219,7 @@ static int
 element_setitem(PyObject* self_, Py_ssize_t index, PyObject* item)
 {
     ElementObject* self = (ElementObject*) self_;
-    int i;
+    Py_ssize_t i;
     PyObject* old;
 
     if (!self->extra || index < 0 || index >= self->extra->length) {
@@ -2076,7 +2076,7 @@ makeuniversal(XMLParserObject* self, const char* string)
     /* convert a UTF-8 tag/attribute name from the expat parser
        to a universal name string */
 
-    int size = strlen(string);
+    Py_ssize_t size = strlen(string);
     PyObject* key;
     PyObject* value;
 
@@ -2572,11 +2572,16 @@ xmlparser_dealloc(XMLParserObject* self)
 /* methods (in alphabetical order) */
 
 LOCAL(PyObject*)
-expat_parse(XMLParserObject* self, char* data, int data_len, int final)
+expat_parse(XMLParserObject* self, char* data, Py_ssize_t data_len, int final)
 {
     int ok;
 
-    ok = EXPAT(Parse)(self->parser, data, data_len, final);
+    if (data_len > INT_MAX) {
+        PyErr_SetString(PyExc_OverflowError, "length doesn't fit in an int");
+        return NULL;
+    }
+
+    ok = EXPAT(Parse)(self->parser, data, (int)data_len, final);
 
     if (PyErr_Occurred())
         return NULL;
diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index bc9b04a..f29a658 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -234,7 +234,7 @@ random_seed(RandomObject *self, PyObject *args)
     if (PyLong_Check(arg))
         n = PyNumber_Absolute(arg);
     else {
-        long hash = PyObject_Hash(arg);
+        Py_hash_t hash = PyObject_Hash(arg);
         if (hash == -1)
             goto Done;
         n = PyLong_FromUnsignedLong((unsigned long)hash);
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 11c68d3..049b20c 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -871,7 +871,7 @@ wrapper_dealloc(wrapperobject *wp)
 static PyObject *
 wrapper_richcompare(PyObject *a, PyObject *b, int op)
 {
-    int result;
+    Py_ssize_t result;
     PyObject *v;
     PyWrapperDescrObject *a_descr, *b_descr;
 
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 10fb8b3..6fbed08 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -464,7 +464,7 @@ static int
 frame_traverse(PyFrameObject *f, visitproc visit, void *arg)
 {
     PyObject **fastlocals, **p;
-    int i, slots;
+    Py_ssize_t i, slots;
 
     Py_VISIT(f->f_back);
     Py_VISIT(f->f_code);
@@ -477,7 +477,8 @@ frame_traverse(PyFrameObject *f, visitproc visit, void *arg)
     Py_VISIT(f->f_exc_traceback);
 
     /* locals */
-    slots = f->f_code->co_nlocals + PyTuple_GET_SIZE(f->f_code->co_cellvars) + PyTuple_GET_SIZE(f->f_code->co_freevars);
+    slots = f->f_code->co_nlocals + PyTuple_GET_SIZE(f->f_code->co_cellvars);
+    slots += PyTuple_GET_SIZE(f->f_code->co_freevars);
     fastlocals = f->f_localsplus;
     for (i = slots; --i >= 0; ++fastlocals)
         Py_VISIT(*fastlocals);
@@ -494,7 +495,7 @@ static void
 frame_clear(PyFrameObject *f)
 {
     PyObject **fastlocals, **p, **oldtop;
-    int i, slots;
+    Py_ssize_t i, slots;
 
     /* Before anything else, make sure that this frame is clearly marked
      * as being defunct!  Else, e.g., a generator reachable from this
@@ -846,7 +847,7 @@ PyFrame_FastToLocals(PyFrameObject *f)
     PyObject *error_type, *error_value, *error_traceback;
     PyCodeObject *co;
     Py_ssize_t j;
-    int ncells, nfreevars;
+    Py_ssize_t ncells, nfreevars;
     if (f == NULL)
         return;
     locals = f->f_locals;
@@ -897,8 +898,7 @@ PyFrame_LocalsToFast(PyFrameObject *f, int clear)
     PyObject **fast;
     PyObject *error_type, *error_value, *error_traceback;
     PyCodeObject *co;
-    Py_ssize_t j;
-    int ncells, nfreevars;
+    Py_ssize_t j, ncells, nfreevars;
     if (f == NULL)
         return;
     locals = f->f_locals;
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 3916262..ad350b6 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -253,7 +253,7 @@ struct pool_header {
     block *freeblock;                   /* pool's free list head         */
     struct pool_header *nextpool;       /* next pool of this size class  */
     struct pool_header *prevpool;       /* previous pool       ""        */
-    uint arenaindex;                    /* index into arenas of base adr */
+    size_t arenaindex;                  /* index into arenas of base adr */
     uint szidx;                         /* block size class index        */
     uint nextoffset;                    /* bytes to virgin block         */
     uint maxnextoffset;                 /* largest valid nextoffset      */
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index 3f6be2f..d74e490 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -663,7 +663,8 @@ translate_into_utf8(const char* str, const char* enc) {
 
 static char *
 translate_newlines(const char *s, int exec_input, struct tok_state *tok) {
-    int skip_next_lf = 0, needed_length = strlen(s) + 2, final_length;
+    int skip_next_lf = 0;
+    size_t needed_length = strlen(s) + 2, final_length;
     char *buf, *current;
     char c = '\0';
     buf = PyMem_MALLOC(needed_length);