diff --git a/Include/bytesobject.h b/Include/bytesobject.h
index d7c7ffd..0ee8d36 100644
--- a/Include/bytesobject.h
+++ b/Include/bytesobject.h
@@ -86,11 +86,11 @@
    0-terminated (passing a string with embedded NULL characters will
    cause an exception).  */
 PyAPI_FUNC(int) PyBytes_AsStringAndSize(
-    register PyObject *obj,	/* string or Unicode object */
-    register char **s,		/* pointer to buffer variable */
-    register Py_ssize_t *len	/* pointer to length variable or NULL
-				   (only possible for 0-terminated
-				   strings) */
+    PyObject *obj,      /* string or Unicode object */
+    char **s,           /* pointer to buffer variable */
+    Py_ssize_t *len     /* pointer to length variable or NULL
+                           (only possible for 0-terminated
+                           strings) */
     );
 
 /* Using the current locale, insert the thousands grouping
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 2abc9b4..6d830c0 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -859,7 +859,7 @@
 */
 
 PyAPI_FUNC(PyObject*) PyUnicode_FromEncodedObject(
-    register PyObject *obj,     /* Object */
+    PyObject *obj,              /* Object */
     const char *encoding,       /* encoding */
     const char *errors          /* error handling */
     );
@@ -878,7 +878,7 @@
 */
 
 PyAPI_FUNC(PyObject*) PyUnicode_FromObject(
-    register PyObject *obj      /* Object */
+    PyObject *obj      /* Object */
     );
 
 PyAPI_FUNC(PyObject *) PyUnicode_FromFormatV(
@@ -1015,7 +1015,7 @@
    The buffer is copied into the new object. */
 
 PyAPI_FUNC(PyObject*) PyUnicode_FromWideChar(
-    register const wchar_t *w,  /* wchar_t buffer */
+    const wchar_t *w,           /* wchar_t buffer */
     Py_ssize_t size             /* size of buffer */
     );
 
@@ -1033,7 +1033,7 @@
 
 PyAPI_FUNC(Py_ssize_t) PyUnicode_AsWideChar(
     PyObject *unicode,          /* Unicode object */
-    register wchar_t *w,        /* wchar_t buffer */
+    wchar_t *w,                 /* wchar_t buffer */
     Py_ssize_t size             /* size of buffer */
     );
 
diff --git a/Misc/NEWS b/Misc/NEWS
index be9e1c4..150a5fe 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,8 @@
 Core and Builtins
 -----------------
 
+- Issue #18722: Remove uses of the "register" keyword in C code.
+
 - Issue #18667: Add missing "HAVE_FCHOWNAT" symbol to posix._have_functions.
 
 - Issue #16499: Add command line option for isolated mode.
diff --git a/Modules/_codecsmodule.c b/Modules/_codecsmodule.c
index 40037b1..0b093ab 100644
--- a/Modules/_codecsmodule.c
+++ b/Modules/_codecsmodule.c
@@ -189,9 +189,9 @@
         return NULL;
     }
     else {
-        register Py_ssize_t i;
-        register char c;
-        register char *p = PyBytes_AS_STRING(v);
+        Py_ssize_t i;
+        char c;
+        char *p = PyBytes_AS_STRING(v);
 
         for (i = 0; i < size; i++) {
             /* There's at least enough room for a hex escape */
diff --git a/Modules/_dbmmodule.c b/Modules/_dbmmodule.c
index 1ce85f5..d899480 100644
--- a/Modules/_dbmmodule.c
+++ b/Modules/_dbmmodule.c
@@ -63,7 +63,7 @@
 /* Methods */
 
 static void
-dbm_dealloc(register dbmobject *dp)
+dbm_dealloc(dbmobject *dp)
 {
     if ( dp->di_dbm )
         dbm_close(dp->di_dbm);
@@ -91,7 +91,7 @@
 }
 
 static PyObject *
-dbm_subscript(dbmobject *dp, register PyObject *key)
+dbm_subscript(dbmobject *dp, PyObject *key)
 {
     datum drec, krec;
     Py_ssize_t tmp_size;
@@ -166,7 +166,7 @@
 };
 
 static PyObject *
-dbm__close(register dbmobject *dp, PyObject *unused)
+dbm__close(dbmobject *dp, PyObject *unused)
 {
     if (dp->di_dbm)
         dbm_close(dp->di_dbm);
@@ -176,9 +176,9 @@
 }
 
 static PyObject *
-dbm_keys(register dbmobject *dp, PyObject *unused)
+dbm_keys(dbmobject *dp, PyObject *unused)
 {
-    register PyObject *v, *item;
+    PyObject *v, *item;
     datum key;
     int err;
 
@@ -249,7 +249,7 @@
 };
 
 static PyObject *
-dbm_get(register dbmobject *dp, PyObject *args)
+dbm_get(dbmobject *dp, PyObject *args)
 {
     datum key, val;
     PyObject *defvalue = Py_None;
@@ -272,7 +272,7 @@
 }
 
 static PyObject *
-dbm_setdefault(register dbmobject *dp, PyObject *args)
+dbm_setdefault(dbmobject *dp, PyObject *args)
 {
     datum key, val;
     PyObject *defvalue = NULL;
diff --git a/Modules/_gdbmmodule.c b/Modules/_gdbmmodule.c
index 474561b..1db021a 100644
--- a/Modules/_gdbmmodule.c
+++ b/Modules/_gdbmmodule.c
@@ -79,7 +79,7 @@
 /* Methods */
 
 static void
-dbm_dealloc(register dbmobject *dp)
+dbm_dealloc(dbmobject *dp)
 {
     if (dp->di_dbm)
         gdbm_close(dp->di_dbm);
@@ -112,7 +112,7 @@
 }
 
 static PyObject *
-dbm_subscript(dbmobject *dp, register PyObject *key)
+dbm_subscript(dbmobject *dp, PyObject *key)
 {
     PyObject *v;
     datum drec, krec;
@@ -232,7 +232,7 @@
 Closes the database.");
 
 static PyObject *
-dbm_close(register dbmobject *dp, PyObject *unused)
+dbm_close(dbmobject *dp, PyObject *unused)
 {
     if (dp->di_dbm)
         gdbm_close(dp->di_dbm);
@@ -247,9 +247,9 @@
 Get a list of all keys in the database.");
 
 static PyObject *
-dbm_keys(register dbmobject *dp, PyObject *unused)
+dbm_keys(dbmobject *dp, PyObject *unused)
 {
-    register PyObject *v, *item;
+    PyObject *v, *item;
     datum key, nextkey;
     int err;
 
@@ -328,9 +328,9 @@
 returns the starting key.");
 
 static PyObject *
-dbm_firstkey(register dbmobject *dp, PyObject *unused)
+dbm_firstkey(dbmobject *dp, PyObject *unused)
 {
-    register PyObject *v;
+    PyObject *v;
     datum key;
 
     check_dbmobject_open(dp);
@@ -358,9 +358,9 @@
           k = db.nextkey(k)");
 
 static PyObject *
-dbm_nextkey(register dbmobject *dp, PyObject *args)
+dbm_nextkey(dbmobject *dp, PyObject *args)
 {
-    register PyObject *v;
+    PyObject *v;
     datum key, nextkey;
 
     if (!PyArg_ParseTuple(args, "s#:nextkey", &key.dptr, &key.dsize))
@@ -387,7 +387,7 @@
 kept and reused as new (key,value) pairs are added.");
 
 static PyObject *
-dbm_reorganize(register dbmobject *dp, PyObject *unused)
+dbm_reorganize(dbmobject *dp, PyObject *unused)
 {
     check_dbmobject_open(dp);
     errno = 0;
@@ -408,7 +408,7 @@
 any unwritten data to be written to the disk.");
 
 static PyObject *
-dbm_sync(register dbmobject *dp, PyObject *unused)
+dbm_sync(dbmobject *dp, PyObject *unused)
 {
     check_dbmobject_open(dp);
     gdbm_sync(dp->di_dbm);
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index f5706dd..75b31f5 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -513,7 +513,7 @@
 static PyObject *
 getarrayitem(PyObject *op, Py_ssize_t i)
 {
-    register arrayobject *ap;
+    arrayobject *ap;
     assert(array_Check(op));
     ap = (arrayobject *)op;
     assert(i>=0 && i<Py_SIZE(ap));
@@ -1225,8 +1225,8 @@
 static PyObject *
 array_reverse(arrayobject *self, PyObject *unused)
 {
-    register Py_ssize_t itemsize = self->ob_descr->itemsize;
-    register char *p, *q;
+    Py_ssize_t itemsize = self->ob_descr->itemsize;
+    char *p, *q;
     /* little buffer to hold items while swapping */
     char tmp[256];      /* 8 is probably enough -- but why skimp */
     assert((size_t)itemsize <= sizeof(tmp));
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index aa38924..6ea654e 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -862,9 +862,9 @@
     /* 15 == strlen(quote_prefix) + 2 + strlen(quote_postfix) + 1 */
     size_t newsize;
     PyObject *v;
-    register Py_ssize_t i;
-    register char c;
-    register char *p;
+    Py_ssize_t i;
+    char c;
+    char *p;
     int quote;
     char *test, *start;
     char *buffer;
@@ -1431,9 +1431,9 @@
 static PyObject *
 bytearray_translate(PyByteArrayObject *self, PyObject *args)
 {
-    register char *input, *output;
-    register const char *table;
-    register Py_ssize_t i, c;
+    char *input, *output;
+    const char *table;
+    Py_ssize_t i, c;
     PyObject *input_obj = (PyObject*)self;
     const char *output_start;
     Py_ssize_t inlen;
diff --git a/Objects/bytes_methods.c b/Objects/bytes_methods.c
index ef3c2f7..4e8107b 100644
--- a/Objects/bytes_methods.c
+++ b/Objects/bytes_methods.c
@@ -10,9 +10,9 @@
 PyObject*
 _Py_bytes_isspace(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
 
     /* Shortcut for single character strings */
     if (len == 1 && Py_ISSPACE(*p))
@@ -40,9 +40,9 @@
 PyObject*
 _Py_bytes_isalpha(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
 
     /* Shortcut for single character strings */
     if (len == 1 && Py_ISALPHA(*p))
@@ -70,9 +70,9 @@
 PyObject*
 _Py_bytes_isalnum(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
 
     /* Shortcut for single character strings */
     if (len == 1 && Py_ISALNUM(*p))
@@ -100,9 +100,9 @@
 PyObject*
 _Py_bytes_isdigit(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
 
     /* Shortcut for single character strings */
     if (len == 1 && Py_ISDIGIT(*p))
@@ -130,9 +130,9 @@
 PyObject*
 _Py_bytes_islower(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
     int cased;
 
     /* Shortcut for single character strings */
@@ -164,9 +164,9 @@
 PyObject*
 _Py_bytes_isupper(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
     int cased;
 
     /* Shortcut for single character strings */
@@ -200,9 +200,9 @@
 PyObject*
 _Py_bytes_istitle(const char *cptr, Py_ssize_t len)
 {
-    register const unsigned char *p
+    const unsigned char *p
         = (unsigned char *) cptr;
-    register const unsigned char *e;
+    const unsigned char *e;
     int cased, previous_is_cased;
 
     /* Shortcut for single character strings */
@@ -217,7 +217,7 @@
     cased = 0;
     previous_is_cased = 0;
     for (; p < e; p++) {
-        register const unsigned char ch = *p;
+        const unsigned char ch = *p;
 
         if (Py_ISUPPER(ch)) {
             if (previous_is_cased)
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 056ac36..3a2906c 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -74,7 +74,7 @@
 PyObject *
 PyBytes_FromStringAndSize(const char *str, Py_ssize_t size)
 {
-    register PyBytesObject *op;
+    PyBytesObject *op;
     if (size < 0) {
         PyErr_SetString(PyExc_SystemError,
             "Negative size passed to PyBytes_FromStringAndSize");
@@ -126,8 +126,8 @@
 PyObject *
 PyBytes_FromString(const char *str)
 {
-    register size_t size;
-    register PyBytesObject *op;
+    size_t size;
+    PyBytesObject *op;
 
     assert(str != NULL);
     size = strlen(str);
@@ -513,7 +513,7 @@
 /* object api */
 
 Py_ssize_t
-PyBytes_Size(register PyObject *op)
+PyBytes_Size(PyObject *op)
 {
     if (!PyBytes_Check(op)) {
         PyErr_Format(PyExc_TypeError,
@@ -524,7 +524,7 @@
 }
 
 char *
-PyBytes_AsString(register PyObject *op)
+PyBytes_AsString(PyObject *op)
 {
     if (!PyBytes_Check(op)) {
         PyErr_Format(PyExc_TypeError,
@@ -535,9 +535,9 @@
 }
 
 int
-PyBytes_AsStringAndSize(register PyObject *obj,
-                         register char **s,
-                         register Py_ssize_t *len)
+PyBytes_AsStringAndSize(PyObject *obj,
+                         char **s,
+                         Py_ssize_t *len)
 {
     if (s == NULL) {
         PyErr_BadInternalCall();
@@ -579,7 +579,7 @@
 PyObject *
 PyBytes_Repr(PyObject *obj, int smartquotes)
 {
-    register PyBytesObject* op = (PyBytesObject*) obj;
+    PyBytesObject* op = (PyBytesObject*) obj;
     Py_ssize_t i, length = Py_SIZE(op);
     size_t newsize, squotes, dquotes;
     PyObject *v;
@@ -718,12 +718,12 @@
 }
 
 static PyObject *
-bytes_repeat(register PyBytesObject *a, register Py_ssize_t n)
+bytes_repeat(PyBytesObject *a, Py_ssize_t n)
 {
-    register Py_ssize_t i;
-    register Py_ssize_t j;
-    register Py_ssize_t size;
-    register PyBytesObject *op;
+    Py_ssize_t i;
+    Py_ssize_t j;
+    Py_ssize_t size;
+    PyBytesObject *op;
     size_t nbytes;
     if (n < 0)
         n = 0;
@@ -793,7 +793,7 @@
 }
 
 static PyObject *
-bytes_item(PyBytesObject *a, register Py_ssize_t i)
+bytes_item(PyBytesObject *a, Py_ssize_t i)
 {
     if (i < 0 || i >= Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError, "index out of range");
@@ -1461,9 +1461,9 @@
 static PyObject *
 bytes_translate(PyBytesObject *self, PyObject *args)
 {
-    register char *input, *output;
+    char *input, *output;
     const char *table;
-    register Py_ssize_t i, c, changed = 0;
+    Py_ssize_t i, c, changed = 0;
     PyObject *input_obj = (PyObject*)self;
     const char *output_start, *del_table=NULL;
     Py_ssize_t inlen, tablen, dellen = 0;
@@ -2748,9 +2748,9 @@
 };
 
 void
-PyBytes_Concat(register PyObject **pv, register PyObject *w)
+PyBytes_Concat(PyObject **pv, PyObject *w)
 {
-    register PyObject *v;
+    PyObject *v;
     assert(pv != NULL);
     if (*pv == NULL)
         return;
@@ -2764,7 +2764,7 @@
 }
 
 void
-PyBytes_ConcatAndDel(register PyObject **pv, register PyObject *w)
+PyBytes_ConcatAndDel(PyObject **pv, PyObject *w)
 {
     PyBytes_Concat(pv, w);
     Py_XDECREF(w);
@@ -2788,8 +2788,8 @@
 int
 _PyBytes_Resize(PyObject **pv, Py_ssize_t newsize)
 {
-    register PyObject *v;
-    register PyBytesObject *sv;
+    PyObject *v;
+    PyBytesObject *sv;
     v = *pv;
     if (!PyBytes_Check(v) || Py_REFCNT(v) != 1 || newsize < 0) {
         *pv = 0;
diff --git a/Objects/classobject.c b/Objects/classobject.c
index cdc9b1c..27f7ef4 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -44,7 +44,7 @@
 PyObject *
 PyMethod_New(PyObject *func, PyObject *self)
 {
-    register PyMethodObject *im;
+    PyMethodObject *im;
     if (self == NULL) {
         PyErr_BadInternalCall();
         return NULL;
@@ -164,7 +164,7 @@
 }
 
 static void
-method_dealloc(register PyMethodObject *im)
+method_dealloc(PyMethodObject *im)
 {
     _PyObject_GC_UNTRACK(im);
     if (im->im_weakreflist != NULL)
@@ -509,7 +509,7 @@
 
 static PyObject *
 instancemethod_descr_get(PyObject *descr, PyObject *obj, PyObject *type) {
-    register PyObject *func = PyInstanceMethod_GET_FUNCTION(descr);
+    PyObject *func = PyInstanceMethod_GET_FUNCTION(descr);
     if (obj == NULL) {
         Py_INCREF(func);
         return func;
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 54838cc..5747450 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -211,7 +211,7 @@
 PyObject *
 PyComplex_FromCComplex(Py_complex cval)
 {
-    register PyComplexObject *op;
+    PyComplexObject *op;
 
     /* Inline PyObject_New */
     op = (PyComplexObject *) PyObject_MALLOC(sizeof(PyComplexObject));
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index e0cb8ac..b5cbfb1 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -467,13 +467,13 @@
 lookdict(PyDictObject *mp, PyObject *key,
          Py_hash_t hash, PyObject ***value_addr)
 {
-    register size_t i;
-    register size_t perturb;
-    register PyDictKeyEntry *freeslot;
-    register size_t mask;
+    size_t i;
+    size_t perturb;
+    PyDictKeyEntry *freeslot;
+    size_t mask;
     PyDictKeyEntry *ep0;
-    register PyDictKeyEntry *ep;
-    register int cmp;
+    PyDictKeyEntry *ep;
+    int cmp;
     PyObject *startkey;
 
 top:
@@ -559,12 +559,12 @@
 lookdict_unicode(PyDictObject *mp, PyObject *key,
                  Py_hash_t hash, PyObject ***value_addr)
 {
-    register size_t i;
-    register size_t perturb;
-    register PyDictKeyEntry *freeslot;
-    register size_t mask = DK_MASK(mp->ma_keys);
+    size_t i;
+    size_t perturb;
+    PyDictKeyEntry *freeslot;
+    size_t mask = DK_MASK(mp->ma_keys);
     PyDictKeyEntry *ep0 = &mp->ma_keys->dk_entries[0];
-    register PyDictKeyEntry *ep;
+    PyDictKeyEntry *ep;
 
     /* Make sure this function doesn't have to handle non-unicode keys,
        including subclasses of str; e.g., one reason to subclass
@@ -624,11 +624,11 @@
 lookdict_unicode_nodummy(PyDictObject *mp, PyObject *key,
                          Py_hash_t hash, PyObject ***value_addr)
 {
-    register size_t i;
-    register size_t perturb;
-    register size_t mask = DK_MASK(mp->ma_keys);
+    size_t i;
+    size_t perturb;
+    size_t mask = DK_MASK(mp->ma_keys);
     PyDictKeyEntry *ep0 = &mp->ma_keys->dk_entries[0];
-    register PyDictKeyEntry *ep;
+    PyDictKeyEntry *ep;
 
     /* Make sure this function doesn't have to handle non-unicode keys,
        including subclasses of str; e.g., one reason to subclass
@@ -669,11 +669,11 @@
 lookdict_split(PyDictObject *mp, PyObject *key,
                Py_hash_t hash, PyObject ***value_addr)
 {
-    register size_t i;
-    register size_t perturb;
-    register size_t mask = DK_MASK(mp->ma_keys);
+    size_t i;
+    size_t perturb;
+    size_t mask = DK_MASK(mp->ma_keys);
     PyDictKeyEntry *ep0 = &mp->ma_keys->dk_entries[0];
-    register PyDictKeyEntry *ep;
+    PyDictKeyEntry *ep;
 
     if (!PyUnicode_CheckExact(key)) {
         ep = lookdict(mp, key, hash, value_addr);
@@ -1498,7 +1498,7 @@
 }
 
 static PyObject *
-dict_subscript(PyDictObject *mp, register PyObject *key)
+dict_subscript(PyDictObject *mp, PyObject *key)
 {
     PyObject *v;
     Py_hash_t hash;
@@ -1554,10 +1554,10 @@
 };
 
 static PyObject *
-dict_keys(register PyDictObject *mp)
+dict_keys(PyDictObject *mp)
 {
-    register PyObject *v;
-    register Py_ssize_t i, j;
+    PyObject *v;
+    Py_ssize_t i, j;
     PyDictKeyEntry *ep;
     Py_ssize_t size, n, offset;
     PyObject **value_ptr;
@@ -1598,10 +1598,10 @@
 }
 
 static PyObject *
-dict_values(register PyDictObject *mp)
+dict_values(PyDictObject *mp)
 {
-    register PyObject *v;
-    register Py_ssize_t i, j;
+    PyObject *v;
+    Py_ssize_t i, j;
     Py_ssize_t size, n, offset;
     PyObject **value_ptr;
 
@@ -1640,10 +1640,10 @@
 }
 
 static PyObject *
-dict_items(register PyDictObject *mp)
+dict_items(PyDictObject *mp)
 {
-    register PyObject *v;
-    register Py_ssize_t i, j, n;
+    PyObject *v;
+    Py_ssize_t i, j, n;
     Py_ssize_t size, offset;
     PyObject *item, *key;
     PyDictKeyEntry *ep;
@@ -1915,8 +1915,8 @@
 int
 PyDict_Merge(PyObject *a, PyObject *b, int override)
 {
-    register PyDictObject *mp, *other;
-    register Py_ssize_t i, n;
+    PyDictObject *mp, *other;
+    Py_ssize_t i, n;
     PyDictKeyEntry *entry;
 
     /* We accept for the argument either a concrete dictionary object,
@@ -2013,7 +2013,7 @@
 }
 
 static PyObject *
-dict_copy(register PyDictObject *mp)
+dict_copy(PyDictObject *mp)
 {
     return PyDict_Copy((PyObject*)mp);
 }
@@ -2175,7 +2175,7 @@
 }
 
 static PyObject *
-dict_contains(register PyDictObject *mp, PyObject *key)
+dict_contains(PyDictObject *mp, PyObject *key)
 {
     Py_hash_t hash;
     PyDictKeyEntry *ep;
@@ -2194,7 +2194,7 @@
 }
 
 static PyObject *
-dict_get(register PyDictObject *mp, PyObject *args)
+dict_get(PyDictObject *mp, PyObject *args)
 {
     PyObject *key;
     PyObject *failobj = Py_None;
@@ -2280,7 +2280,7 @@
 }
 
 static PyObject *
-dict_clear(register PyDictObject *mp)
+dict_clear(PyDictObject *mp)
 {
     PyDict_Clear((PyObject *)mp);
     Py_RETURN_NONE;
@@ -2824,8 +2824,8 @@
 static PyObject *dictiter_iternextkey(dictiterobject *di)
 {
     PyObject *key;
-    register Py_ssize_t i, mask, offset;
-    register PyDictKeysObject *k;
+    Py_ssize_t i, mask, offset;
+    PyDictKeysObject *k;
     PyDictObject *d = di->di_dict;
     PyObject **value_ptr;
 
@@ -2907,7 +2907,7 @@
 static PyObject *dictiter_iternextvalue(dictiterobject *di)
 {
     PyObject *value;
-    register Py_ssize_t i, mask, offset;
+    Py_ssize_t i, mask, offset;
     PyDictObject *d = di->di_dict;
     PyObject **value_ptr;
 
@@ -2988,7 +2988,7 @@
 static PyObject *dictiter_iternextitem(dictiterobject *di)
 {
     PyObject *key, *value, *result = di->di_result;
-    register Py_ssize_t i, mask, offset;
+    Py_ssize_t i, mask, offset;
     PyDictObject *d = di->di_dict;
     PyObject **value_ptr;
 
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 7ee2034..fea83fa 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -109,7 +109,7 @@
 PyObject *
 PyFloat_FromDouble(double fval)
 {
-    register PyFloatObject *op = free_list;
+    PyFloatObject *op = free_list;
     if (op != NULL) {
         free_list = (PyFloatObject *) Py_TYPE(op);
         numfree--;
@@ -241,7 +241,7 @@
 static int
 convert_to_double(PyObject **v, double *dbl)
 {
-    register PyObject *obj = *v;
+    PyObject *obj = *v;
 
     if (PyLong_Check(obj)) {
         *dbl = PyLong_AsDouble(obj);
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 2f203b3..c08c1f6 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -213,11 +213,11 @@
 }
 
 int
-PyList_SetItem(register PyObject *op, register Py_ssize_t i,
-               register PyObject *newitem)
+PyList_SetItem(PyObject *op, Py_ssize_t i,
+               PyObject *newitem)
 {
-    register PyObject *olditem;
-    register PyObject **p;
+    PyObject *olditem;
+    PyObject **p;
     if (!PyList_Check(op)) {
         Py_XDECREF(newitem);
         PyErr_BadInternalCall();
@@ -1058,9 +1058,9 @@
 static int
 binarysort(sortslice lo, PyObject **hi, PyObject **start)
 {
-    register Py_ssize_t k;
-    register PyObject **l, **p, **r;
-    register PyObject *pivot;
+    Py_ssize_t k;
+    PyObject **l, **p, **r;
+    PyObject *pivot;
 
     assert(lo.keys <= start && start <= hi);
     /* assert [lo, start) is sorted */
diff --git a/Objects/longobject.c b/Objects/longobject.c
index e0d641a0..9784734 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -110,7 +110,7 @@
    of the algorithms used, this could save at most be one word anyway. */
 
 static PyLongObject *
-long_normalize(register PyLongObject *v)
+long_normalize(PyLongObject *v)
 {
     Py_ssize_t j = ABS(Py_SIZE(v));
     Py_ssize_t i = j;
@@ -340,7 +340,7 @@
 PyLong_AsLongAndOverflow(PyObject *vv, int *overflow)
 {
     /* This version by Tim Peters */
-    register PyLongObject *v;
+    PyLongObject *v;
     unsigned long x, prev;
     long res;
     Py_ssize_t i;
@@ -463,7 +463,7 @@
 
 Py_ssize_t
 PyLong_AsSsize_t(PyObject *vv) {
-    register PyLongObject *v;
+    PyLongObject *v;
     size_t x, prev;
     Py_ssize_t i;
     int sign;
@@ -519,7 +519,7 @@
 unsigned long
 PyLong_AsUnsignedLong(PyObject *vv)
 {
-    register PyLongObject *v;
+    PyLongObject *v;
     unsigned long x, prev;
     Py_ssize_t i;
 
@@ -563,7 +563,7 @@
 size_t
 PyLong_AsSize_t(PyObject *vv)
 {
-    register PyLongObject *v;
+    PyLongObject *v;
     size_t x, prev;
     Py_ssize_t i;
 
@@ -606,7 +606,7 @@
 static unsigned long
 _PyLong_AsUnsignedLongMask(PyObject *vv)
 {
-    register PyLongObject *v;
+    PyLongObject *v;
     unsigned long x;
     Py_ssize_t i;
     int sign;
@@ -634,7 +634,7 @@
 }
 
 unsigned long
-PyLong_AsUnsignedLongMask(register PyObject *op)
+PyLong_AsUnsignedLongMask(PyObject *op)
 {
     PyNumberMethods *nb;
     PyLongObject *lo;
@@ -1250,7 +1250,7 @@
 static unsigned PY_LONG_LONG
 _PyLong_AsUnsignedLongLongMask(PyObject *vv)
 {
-    register PyLongObject *v;
+    PyLongObject *v;
     unsigned PY_LONG_LONG x;
     Py_ssize_t i;
     int sign;
@@ -1278,7 +1278,7 @@
 }
 
 unsigned PY_LONG_LONG
-PyLong_AsUnsignedLongLongMask(register PyObject *op)
+PyLong_AsUnsignedLongLongMask(PyObject *op)
 {
     PyNumberMethods *nb;
     PyLongObject *lo;
@@ -1326,7 +1326,7 @@
 PyLong_AsLongLongAndOverflow(PyObject *vv, int *overflow)
 {
     /* This version by Tim Peters */
-    register PyLongObject *v;
+    PyLongObject *v;
     unsigned PY_LONG_LONG x, prev;
     PY_LONG_LONG res;
     Py_ssize_t i;
@@ -1744,7 +1744,7 @@
 long_format_binary(PyObject *aa, int base, int alternate,
                    PyObject **p_output, _PyUnicodeWriter *writer)
 {
-    register PyLongObject *a = (PyLongObject *)aa;
+    PyLongObject *a = (PyLongObject *)aa;
     PyObject *v;
     Py_ssize_t sz;
     Py_ssize_t size_a;
@@ -2141,7 +2141,7 @@
 just 1 digit at the start, so that the copying code was exercised for every
 digit beyond the first.
 ***/
-        register twodigits c;           /* current input character */
+        twodigits c;           /* current input character */
         Py_ssize_t size_z;
         int i;
         int convwidth;
diff --git a/Objects/namespaceobject.c b/Objects/namespaceobject.c
index 8c51b07..9e95094 100644
--- a/Objects/namespaceobject.c
+++ b/Objects/namespaceobject.c
@@ -176,7 +176,7 @@
 PyDoc_STRVAR(namespace_reduce__doc__, "Return state information for pickling");
 
 static PyObject *
-namespace_reduce(register _PyNamespaceObject *ns)
+namespace_reduce(_PyNamespaceObject *ns)
 {
     PyObject *result, *args = PyTuple_New(0);
 
diff --git a/Objects/object.c b/Objects/object.c
index c83109d..8d4fe42 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1834,10 +1834,10 @@
 }
 
 void
-_Py_ForgetReference(register PyObject *op)
+_Py_ForgetReference(PyObject *op)
 {
 #ifdef SLOW_UNREF_CHECK
-    register PyObject *p;
+    PyObject *p;
 #endif
     if (op->ob_refcnt < 0)
         Py_FatalError("UNREF negative refcnt");
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 0cea2a8..eff91c5 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -75,15 +75,15 @@
 */
 
 static setentry *
-set_lookkey(PySetObject *so, PyObject *key, register Py_hash_t hash)
+set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
 {
-    register size_t i;  /* Unsigned for defined overflow behavior. */
-    register size_t perturb;
-    register setentry *freeslot;
-    register size_t mask = so->mask;
+    size_t i;  /* Unsigned for defined overflow behavior. */
+    size_t perturb;
+    setentry *freeslot;
+    size_t mask = so->mask;
     setentry *table = so->table;
-    register setentry *entry;
-    register int cmp;
+    setentry *entry;
+    int cmp;
     PyObject *startkey;
 
     i = (size_t)hash & mask;
@@ -157,14 +157,14 @@
  * see if the comparison altered the table.
  */
 static setentry *
-set_lookkey_unicode(PySetObject *so, PyObject *key, register Py_hash_t hash)
+set_lookkey_unicode(PySetObject *so, PyObject *key, Py_hash_t hash)
 {
-    register size_t i;  /* Unsigned for defined overflow behavior. */
-    register size_t perturb;
-    register setentry *freeslot;
-    register size_t mask = so->mask;
+    size_t i;  /* Unsigned for defined overflow behavior. */
+    size_t perturb;
+    setentry *freeslot;
+    size_t mask = so->mask;
     setentry *table = so->table;
-    register setentry *entry;
+    setentry *entry;
 
     /* Make sure this function doesn't have to handle non-unicode keys,
        including subclasses of str; e.g., one reason to subclass
@@ -211,9 +211,9 @@
 Eats a reference to key.
 */
 static int
-set_insert_key(register PySetObject *so, PyObject *key, Py_hash_t hash)
+set_insert_key(PySetObject *so, PyObject *key, Py_hash_t hash)
 {
-    register setentry *entry;
+    setentry *entry;
 
     assert(so->lookup != NULL);
     entry = so->lookup(so, key, hash);
@@ -247,13 +247,13 @@
 is responsible for incref'ing `key`.
 */
 static void
-set_insert_clean(register PySetObject *so, PyObject *key, Py_hash_t hash)
+set_insert_clean(PySetObject *so, PyObject *key, Py_hash_t hash)
 {
-    register size_t i;
-    register size_t perturb;
-    register size_t mask = (size_t)so->mask;
+    size_t i;
+    size_t perturb;
+    size_t mask = (size_t)so->mask;
     setentry *table = so->table;
-    register setentry *entry;
+    setentry *entry;
 
     i = (size_t)hash & mask;
     entry = &table[i];
@@ -360,9 +360,9 @@
 /* CAUTION: set_add_key/entry() must guarantee it won't resize the table */
 
 static int
-set_add_entry(register PySetObject *so, setentry *entry)
+set_add_entry(PySetObject *so, setentry *entry)
 {
-    register Py_ssize_t n_used;
+    Py_ssize_t n_used;
     PyObject *key = entry->key;
     Py_hash_t hash = entry->hash;
 
@@ -379,10 +379,10 @@
 }
 
 static int
-set_add_key(register PySetObject *so, PyObject *key)
+set_add_key(PySetObject *so, PyObject *key)
 {
-    register Py_hash_t hash;
-    register Py_ssize_t n_used;
+    Py_hash_t hash;
+    Py_ssize_t n_used;
 
     if (!PyUnicode_CheckExact(key) ||
         (hash = ((PyASCIIObject *) key)->hash) == -1) {
@@ -407,7 +407,7 @@
 
 static int
 set_discard_entry(PySetObject *so, setentry *oldentry)
-{       register setentry *entry;
+{       setentry *entry;
     PyObject *old_key;
 
     entry = (so->lookup)(so, oldentry->key, oldentry->hash);
@@ -426,8 +426,8 @@
 static int
 set_discard_key(PySetObject *so, PyObject *key)
 {
-    register Py_hash_t hash;
-    register setentry *entry;
+    Py_hash_t hash;
+    setentry *entry;
     PyObject *old_key;
 
     assert (PyAnySet_Check(so));
@@ -533,7 +533,7 @@
 {
     Py_ssize_t i;
     Py_ssize_t mask;
-    register setentry *table;
+    setentry *table;
 
     assert (PyAnySet_Check(so));
     i = *pos_ptr;
@@ -553,7 +553,7 @@
 static void
 set_dealloc(PySetObject *so)
 {
-    register setentry *entry;
+    setentry *entry;
     Py_ssize_t fill = so->fill;
     PyObject_GC_UnTrack(so);
     Py_TRASHCAN_SAFE_BEGIN(so)
@@ -632,8 +632,8 @@
     PySetObject *other;
     PyObject *key;
     Py_hash_t hash;
-    register Py_ssize_t i;
-    register setentry *entry;
+    Py_ssize_t i;
+    setentry *entry;
 
     assert (PyAnySet_Check(so));
     assert (PyAnySet_Check(otherset));
@@ -701,8 +701,8 @@
 static PyObject *
 set_pop(PySetObject *so)
 {
-    register Py_ssize_t i = 0;
-    register setentry *entry;
+    Py_ssize_t i = 0;
+    setentry *entry;
     PyObject *key;
 
     assert (PyAnySet_Check(so));
@@ -869,8 +869,8 @@
 static PyObject *setiter_iternext(setiterobject *si)
 {
     PyObject *key;
-    register Py_ssize_t i, mask;
-    register setentry *entry;
+    Py_ssize_t i, mask;
+    setentry *entry;
     PySetObject *so = si->si_set;
 
     if (so == NULL)
@@ -1024,7 +1024,7 @@
 static PyObject *
 make_new_set(PyTypeObject *type, PyObject *iterable)
 {
-    register PySetObject *so = NULL;
+    PySetObject *so = NULL;
 
     if (dummy == NULL) { /* Auto-initialize dummy */
         dummy = PyUnicode_FromString("<dummy key>");
diff --git a/Objects/stringlib/codecs.h b/Objects/stringlib/codecs.h
index f855003..57319c6 100644
--- a/Objects/stringlib/codecs.h
+++ b/Objects/stringlib/codecs.h
@@ -38,8 +38,8 @@
             */
             if (_Py_IS_ALIGNED(s, SIZEOF_LONG)) {
                 /* Help register allocation */
-                register const char *_s = s;
-                register STRINGLIB_CHAR *_p = p;
+                const char *_s = s;
+                STRINGLIB_CHAR *_p = p;
                 while (_s < aligned_end) {
                     /* Read a whole long at a time (either 4 or 8 bytes),
                        and do a fast unrolled copy if it only contains ASCII
@@ -499,7 +499,7 @@
            reads are more expensive, better to defer to another iteration. */
         if (_Py_IS_ALIGNED(q, SIZEOF_LONG)) {
             /* Fast path for runs of in-range non-surrogate chars. */
-            register const unsigned char *_q = q;
+            const unsigned char *_q = q;
             while (_q < aligned_end) {
                 unsigned long block = * (unsigned long *) _q;
                 if (native_ordering) {
diff --git a/Objects/stringlib/eq.h b/Objects/stringlib/eq.h
index 8e79a43..4ad6dc0 100644
--- a/Objects/stringlib/eq.h
+++ b/Objects/stringlib/eq.h
@@ -6,8 +6,8 @@
 Py_LOCAL_INLINE(int)
 unicode_eq(PyObject *aa, PyObject *bb)
 {
-    register PyUnicodeObject *a = (PyUnicodeObject *)aa;
-    register PyUnicodeObject *b = (PyUnicodeObject *)bb;
+    PyUnicodeObject *a = (PyUnicodeObject *)aa;
+    PyUnicodeObject *b = (PyUnicodeObject *)bb;
 
     if (PyUnicode_READY(a) == -1 || PyUnicode_READY(b) == -1) {
         assert(0 && "unicode_eq ready fail");
diff --git a/Objects/stringlib/find_max_char.h b/Objects/stringlib/find_max_char.h
index 06559c8..eb3fe88 100644
--- a/Objects/stringlib/find_max_char.h
+++ b/Objects/stringlib/find_max_char.h
@@ -24,7 +24,7 @@
     while (p < end) {
         if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
             /* Help register allocation */
-            register const unsigned char *_p = p;
+            const unsigned char *_p = p;
             while (_p < aligned_end) {
                 unsigned long value = *(unsigned long *) _p;
                 if (value & UCS1_ASCII_CHAR_MASK)
@@ -66,7 +66,7 @@
 #else
 #error Invalid STRINGLIB_SIZEOF_CHAR (must be 1, 2 or 4)
 #endif
-    register Py_UCS4 mask;
+    Py_UCS4 mask;
     Py_ssize_t n = end - begin;
     const STRINGLIB_CHAR *p = begin;
     const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
diff --git a/Objects/stringlib/split.h b/Objects/stringlib/split.h
index 947dd28..31f77a7 100644
--- a/Objects/stringlib/split.h
+++ b/Objects/stringlib/split.h
@@ -345,8 +345,8 @@
        and the appends only done when the prealloc buffer is full.
        That's too much work for little gain.*/
 
-    register Py_ssize_t i;
-    register Py_ssize_t j;
+    Py_ssize_t i;
+    Py_ssize_t j;
     PyObject *list = PyList_New(0);
     PyObject *sub;
 
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 52896b7..a33d8c0 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -63,9 +63,9 @@
 }
 
 PyObject *
-PyTuple_New(register Py_ssize_t size)
+PyTuple_New(Py_ssize_t size)
 {
-    register PyTupleObject *op;
+    PyTupleObject *op;
     Py_ssize_t i;
     if (size < 0) {
         PyErr_BadInternalCall();
@@ -122,7 +122,7 @@
 }
 
 Py_ssize_t
-PyTuple_Size(register PyObject *op)
+PyTuple_Size(PyObject *op)
 {
     if (!PyTuple_Check(op)) {
         PyErr_BadInternalCall();
@@ -133,7 +133,7 @@
 }
 
 PyObject *
-PyTuple_GetItem(register PyObject *op, register Py_ssize_t i)
+PyTuple_GetItem(PyObject *op, Py_ssize_t i)
 {
     if (!PyTuple_Check(op)) {
         PyErr_BadInternalCall();
@@ -147,10 +147,10 @@
 }
 
 int
-PyTuple_SetItem(register PyObject *op, register Py_ssize_t i, PyObject *newitem)
+PyTuple_SetItem(PyObject *op, Py_ssize_t i, PyObject *newitem)
 {
-    register PyObject *olditem;
-    register PyObject **p;
+    PyObject *olditem;
+    PyObject **p;
     if (!PyTuple_Check(op) || op->ob_refcnt != 1) {
         Py_XDECREF(newitem);
         PyErr_BadInternalCall();
@@ -224,10 +224,10 @@
 /* Methods */
 
 static void
-tupledealloc(register PyTupleObject *op)
+tupledealloc(PyTupleObject *op)
 {
-    register Py_ssize_t i;
-    register Py_ssize_t len =  Py_SIZE(op);
+    Py_ssize_t i;
+    Py_ssize_t len =  Py_SIZE(op);
     PyObject_GC_UnTrack(op);
     Py_TRASHCAN_SAFE_BEGIN(op)
     if (len > 0) {
@@ -330,10 +330,10 @@
 static Py_hash_t
 tuplehash(PyTupleObject *v)
 {
-    register Py_uhash_t x;  /* Unsigned for defined overflow behavior. */
-    register Py_hash_t y;
-    register Py_ssize_t len = Py_SIZE(v);
-    register PyObject **p;
+    Py_uhash_t x;  /* Unsigned for defined overflow behavior. */
+    Py_hash_t y;
+    Py_ssize_t len = Py_SIZE(v);
+    PyObject **p;
     Py_uhash_t mult = _PyHASH_MULTIPLIER;
     x = 0x345678UL;
     p = v->ob_item;
@@ -370,7 +370,7 @@
 }
 
 static PyObject *
-tupleitem(register PyTupleObject *a, register Py_ssize_t i)
+tupleitem(PyTupleObject *a, Py_ssize_t i)
 {
     if (i < 0 || i >= Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError, "tuple index out of range");
@@ -381,12 +381,12 @@
 }
 
 static PyObject *
-tupleslice(register PyTupleObject *a, register Py_ssize_t ilow,
-           register Py_ssize_t ihigh)
+tupleslice(PyTupleObject *a, Py_ssize_t ilow,
+           Py_ssize_t ihigh)
 {
-    register PyTupleObject *np;
+    PyTupleObject *np;
     PyObject **src, **dest;
-    register Py_ssize_t i;
+    Py_ssize_t i;
     Py_ssize_t len;
     if (ilow < 0)
         ilow = 0;
@@ -423,10 +423,10 @@
 }
 
 static PyObject *
-tupleconcat(register PyTupleObject *a, register PyObject *bb)
+tupleconcat(PyTupleObject *a, PyObject *bb)
 {
-    register Py_ssize_t size;
-    register Py_ssize_t i;
+    Py_ssize_t size;
+    Py_ssize_t i;
     PyObject **src, **dest;
     PyTupleObject *np;
     if (!PyTuple_Check(bb)) {
@@ -836,8 +836,8 @@
 int
 _PyTuple_Resize(PyObject **pv, Py_ssize_t newsize)
 {
-    register PyTupleObject *v;
-    register PyTupleObject *sv;
+    PyTupleObject *v;
+    PyTupleObject *sv;
     Py_ssize_t i;
     Py_ssize_t oldsize;
 
diff --git a/Objects/unicodectype.c b/Objects/unicodectype.c
index a572c12..ea540d6 100644
--- a/Objects/unicodectype.c
+++ b/Objects/unicodectype.c
@@ -61,7 +61,7 @@
 /* Returns the titlecase Unicode characters corresponding to ch or just
    ch if no titlecase mapping is known. */
 
-Py_UCS4 _PyUnicode_ToTitlecase(register Py_UCS4 ch)
+Py_UCS4 _PyUnicode_ToTitlecase(Py_UCS4 ch)
 {
     const _PyUnicode_TypeRecord *ctype = gettyperecord(ch);
 
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 2f437f6..f1d687a 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -873,7 +873,7 @@
 static PyUnicodeObject *
 _PyUnicode_New(Py_ssize_t length)
 {
-    register PyUnicodeObject *unicode;
+    PyUnicodeObject *unicode;
     size_t new_size;
 
     /* Optimization for empty strings */
@@ -1557,7 +1557,7 @@
 }
 
 static void
-unicode_dealloc(register PyObject *unicode)
+unicode_dealloc(PyObject *unicode)
 {
     switch (PyUnicode_CHECK_INTERNED(unicode)) {
     case SSTATE_NOT_INTERNED:
@@ -2287,7 +2287,7 @@
 #ifdef HAVE_WCHAR_H
 
 PyObject *
-PyUnicode_FromWideChar(register const wchar_t *w, Py_ssize_t size)
+PyUnicode_FromWideChar(const wchar_t *w, Py_ssize_t size)
 {
     if (w == NULL) {
         if (size == 0)
@@ -2898,7 +2898,7 @@
 }
 
 PyObject *
-PyUnicode_FromObject(register PyObject *obj)
+PyUnicode_FromObject(PyObject *obj)
 {
     /* XXX Perhaps we should make this API an alias of
        PyObject_Str() instead ?! */
@@ -2920,7 +2920,7 @@
 }
 
 PyObject *
-PyUnicode_FromEncodedObject(register PyObject *obj,
+PyUnicode_FromEncodedObject(PyObject *obj,
                             const char *encoding,
                             const char *errors)
 {
@@ -4653,9 +4653,9 @@
     if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
         /* Fast path, see in STRINGLIB(utf8_decode) for
            an explanation. */
-        /* Help register allocation */
-        register const char *_p = p;
-        register Py_UCS1 * q = dest;
+        /* Help allocation */
+        const char *_p = p;
+        Py_UCS1 * q = dest;
         while (_p < aligned_end) {
             unsigned long value = *(const unsigned long *) _p;
             if (value & ASCII_CHAR_MASK)
@@ -4678,8 +4678,8 @@
         /* Fast path, see in STRINGLIB(utf8_decode) in stringlib/codecs.h
            for an explanation. */
         if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
-            /* Help register allocation */
-            register const char *_p = p;
+            /* Help allocation */
+            const char *_p = p;
             while (_p < aligned_end) {
                 unsigned long value = *(unsigned long *) _p;
                 if (value & ASCII_CHAR_MASK)
@@ -6513,7 +6513,7 @@
     s += writer.pos;
     kind = writer.kind;
     while (s < e) {
-        register unsigned char c = (unsigned char)*s;
+        unsigned char c = (unsigned char)*s;
         if (c < 128) {
             PyUnicode_WRITE(kind, data, writer.pos, c);
             writer.pos++;
@@ -14621,7 +14621,7 @@
 void
 PyUnicode_InternInPlace(PyObject **p)
 {
-    register PyObject *s = *p;
+    PyObject *s = *p;
     PyObject *t;
 #ifdef Py_DEBUG
     assert(s != NULL);
@@ -14954,7 +14954,7 @@
 int
 Py_UNICODE_strncmp(const Py_UNICODE *s1, const Py_UNICODE *s2, size_t n)
 {
-    register Py_UNICODE u1, u2;
+    Py_UNICODE u1, u2;
     for (; n != 0; n--) {
         u1 = *s1;
         u2 = *s2;
diff --git a/Objects/unicodetype_db.h b/Objects/unicodetype_db.h
index 1009bb3..57add8f 100644
--- a/Objects/unicodetype_db.h
+++ b/Objects/unicodetype_db.h
@@ -4278,7 +4278,7 @@
 /* Returns 1 for Unicode characters having the bidirectional
  * type 'WS', 'B' or 'S' or the category 'Zs', 0 otherwise.
  */
-int _PyUnicode_IsWhitespace(register const Py_UCS4 ch)
+int _PyUnicode_IsWhitespace(const Py_UCS4 ch)
 {
     switch (ch) {
     case 0x0009:
@@ -4320,7 +4320,7 @@
  * property 'BK', 'CR', 'LF' or 'NL' or having bidirectional
  * type 'B', 0 otherwise.
  */
-int _PyUnicode_IsLinebreak(register const Py_UCS4 ch)
+int _PyUnicode_IsLinebreak(const Py_UCS4 ch)
 {
     switch (ch) {
     case 0x000A:
diff --git a/Parser/grammar1.c b/Parser/grammar1.c
index 7136463..30a6f07 100644
--- a/Parser/grammar1.c
+++ b/Parser/grammar1.c
@@ -9,9 +9,9 @@
 /* Return the DFA for the given type */
 
 dfa *
-PyGrammar_FindDFA(grammar *g, register int type)
+PyGrammar_FindDFA(grammar *g, int type)
 {
-    register dfa *d;
+    dfa *d;
 #if 1
     /* Massive speed-up */
     d = &g->g_dfa[type - NT_OFFSET];
@@ -19,7 +19,7 @@
     return d;
 #else
     /* Old, slow version */
-    register int i;
+    int i;
 
     for (i = g->g_ndfas, d = g->g_dfa; --i >= 0; d++) {
         if (d->d_type == type)
diff --git a/Parser/node.c b/Parser/node.c
index 1e4f0da..b26ce61 100644
--- a/Parser/node.c
+++ b/Parser/node.c
@@ -76,7 +76,7 @@
 
 
 int
-PyNode_AddChild(register node *n1, int type, char *str, int lineno, int col_offset)
+PyNode_AddChild(node *n1, int type, char *str, int lineno, int col_offset)
 {
     const int nch = n1->n_nchildren;
     int current_capacity;
diff --git a/Parser/parser.c b/Parser/parser.c
index b505fe0..fc102f2 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -35,9 +35,9 @@
 #define s_empty(s) ((s)->s_top == &(s)->s_base[MAXSTACK])
 
 static int
-s_push(register stack *s, dfa *d, node *parent)
+s_push(stack *s, dfa *d, node *parent)
 {
-    register stackentry *top;
+    stackentry *top;
     if (s->s_top == s->s_base) {
         fprintf(stderr, "s_push: parser stack overflow\n");
         return E_NOMEM;
@@ -52,7 +52,7 @@
 #ifdef Py_DEBUG
 
 static void
-s_pop(register stack *s)
+s_pop(stack *s)
 {
     if (s_empty(s))
         Py_FatalError("s_pop: parser stack underflow -- FATAL");
@@ -105,7 +105,7 @@
 /* PARSER STACK OPERATIONS */
 
 static int
-shift(register stack *s, int type, char *str, int newstate, int lineno, int col_offset)
+shift(stack *s, int type, char *str, int newstate, int lineno, int col_offset)
 {
     int err;
     assert(!s_empty(s));
@@ -117,10 +117,10 @@
 }
 
 static int
-push(register stack *s, int type, dfa *d, int newstate, int lineno, int col_offset)
+push(stack *s, int type, dfa *d, int newstate, int lineno, int col_offset)
 {
     int err;
-    register node *n;
+    node *n;
     n = s->s_top->s_parent;
     assert(!s_empty(s));
     err = PyNode_AddChild(n, type, (char *)NULL, lineno, col_offset);
@@ -137,12 +137,12 @@
 classify(parser_state *ps, int type, char *str)
 {
     grammar *g = ps->p_grammar;
-    register int n = g->g_ll.ll_nlabels;
+    int n = g->g_ll.ll_nlabels;
 
     if (type == NAME) {
-        register char *s = str;
-        register label *l = g->g_ll.ll_label;
-        register int i;
+        char *s = str;
+        label *l = g->g_ll.ll_label;
+        int i;
         for (i = n; i > 0; i--, l++) {
             if (l->lb_type != NAME || l->lb_str == NULL ||
                 l->lb_str[0] != s[0] ||
@@ -165,8 +165,8 @@
     }
 
     {
-        register label *l = g->g_ll.ll_label;
-        register int i;
+        label *l = g->g_ll.ll_label;
+        int i;
         for (i = n; i > 0; i--, l++) {
             if (l->lb_type == type && l->lb_str == NULL) {
                 D(printf("It's a token we know\n"));
@@ -225,10 +225,10 @@
 #endif /* future keyword */
 
 int
-PyParser_AddToken(register parser_state *ps, register int type, char *str,
+PyParser_AddToken(parser_state *ps, int type, char *str,
                   int lineno, int col_offset, int *expected_ret)
 {
-    register int ilabel;
+    int ilabel;
     int err;
 
     D(printf("Token %s/'%s' ... ", _PyParser_TokenNames[type], str));
@@ -241,15 +241,15 @@
     /* Loop until the token is shifted or an error occurred */
     for (;;) {
         /* Fetch the current dfa and state */
-        register dfa *d = ps->p_stack.s_top->s_dfa;
-        register state *s = &d->d_state[ps->p_stack.s_top->s_state];
+        dfa *d = ps->p_stack.s_top->s_dfa;
+        state *s = &d->d_state[ps->p_stack.s_top->s_state];
 
         D(printf(" DFA '%s', state %d:",
             d->d_name, ps->p_stack.s_top->s_state));
 
         /* Check accelerator */
         if (s->s_lower <= ilabel && ilabel < s->s_upper) {
-            register int x = s->s_accel[ilabel - s->s_lower];
+            int x = s->s_accel[ilabel - s->s_lower];
             if (x != -1) {
                 if (x & (1<<7)) {
                     /* Push non-terminal */
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index c4160fc..97990e9 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -874,7 +874,7 @@
 /* Get next char, updating state; error code goes into tok->done */
 
 static int
-tok_nextc(register struct tok_state *tok)
+tok_nextc(struct tok_state *tok)
 {
     for (;;) {
         if (tok->cur != tok->inp) {
@@ -1071,7 +1071,7 @@
 /* Back-up one character */
 
 static void
-tok_backup(register struct tok_state *tok, register int c)
+tok_backup(struct tok_state *tok, int c)
 {
     if (c != EOF) {
         if (--tok->cur < tok->buf)
@@ -1301,9 +1301,9 @@
 /* Get next token, after space stripping etc. */
 
 static int
-tok_get(register struct tok_state *tok, char **p_start, char **p_end)
+tok_get(struct tok_state *tok, char **p_start, char **p_end)
 {
-    register int c;
+    int c;
     int blankline, nonascii;
 
     *p_start = *p_end = NULL;
@@ -1313,8 +1313,8 @@
 
     /* Get indentation level */
     if (tok->atbol) {
-        register int col = 0;
-        register int altcol = 0;
+        int col = 0;
+        int altcol = 0;
         tok->atbol = 0;
         for (;;) {
             c = tok_nextc(tok);
diff --git a/Python/ceval.c b/Python/ceval.c
index 465876b..fcc1c24 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -37,7 +37,7 @@
 static void
 ppc_getcounter(uint64 *v)
 {
-    register unsigned long tbu, tb, tbu2;
+    unsigned long tbu, tb, tbu2;
 
   loop:
     asm volatile ("mftbu %0" : "=r" (tbu) );
@@ -792,12 +792,12 @@
 #ifdef DXPAIRS
     int lastopcode = 0;
 #endif
-    register PyObject **stack_pointer;  /* Next free slot in value stack */
-    register unsigned char *next_instr;
-    register int opcode;        /* Current opcode */
-    register int oparg;         /* Current opcode argument, if any */
-    register enum why_code why; /* Reason for block stack unwind */
-    register PyObject **fastlocals, **freevars;
+    PyObject **stack_pointer;  /* Next free slot in value stack */
+    unsigned char *next_instr;
+    int opcode;        /* Current opcode */
+    int oparg;         /* Current opcode argument, if any */
+    enum why_code why; /* Reason for block stack unwind */
+    PyObject **fastlocals, **freevars;
     PyObject *retval = NULL;            /* Return value */
     PyThreadState *tstate = PyThreadState_GET();
     PyCodeObject *co;
@@ -3373,9 +3373,9 @@
            PyObject **defs, int defcount, PyObject *kwdefs, PyObject *closure)
 {
     PyCodeObject* co = (PyCodeObject*)_co;
-    register PyFrameObject *f;
-    register PyObject *retval = NULL;
-    register PyObject **fastlocals, **freevars;
+    PyFrameObject *f;
+    PyObject *retval = NULL;
+    PyObject **fastlocals, **freevars;
     PyThreadState *tstate = PyThreadState_GET();
     PyObject *x, *u;
     int total_args = co->co_argcount + co->co_kwonlyargcount;
@@ -3895,7 +3895,7 @@
 call_trace(Py_tracefunc func, PyObject *obj, PyFrameObject *frame,
            int what, PyObject *arg)
 {
-    register PyThreadState *tstate = frame->f_tstate;
+    PyThreadState *tstate = frame->f_tstate;
     int result;
     if (tstate->tracing)
         return 0;
@@ -4581,7 +4581,7 @@
                          "BaseException is not allowed"
 
 static PyObject *
-cmp_outcome(int op, register PyObject *v, register PyObject *w)
+cmp_outcome(int op, PyObject *v, PyObject *w)
 {
     int res = 0;
     switch (op) {
diff --git a/Python/codecs.c b/Python/codecs.c
index 899f0aa..cb9f0d8 100644
--- a/Python/codecs.c
+++ b/Python/codecs.c
@@ -53,7 +53,7 @@
 static
 PyObject *normalizestring(const char *string)
 {
-    register size_t i;
+    size_t i;
     size_t len = strlen(string);
     char *p;
     PyObject *v;
@@ -67,7 +67,7 @@
     if (p == NULL)
         return PyErr_NoMemory();
     for (i = 0; i < len; i++) {
-        register char ch = string[i];
+        char ch = string[i];
         if (ch == ' ')
             ch = '-';
         else
diff --git a/Python/dynload_aix.c b/Python/dynload_aix.c
index f40a0be..5ac30ed 100644
--- a/Python/dynload_aix.c
+++ b/Python/dynload_aix.c
@@ -30,11 +30,11 @@
 static int
 aix_getoldmodules(void **modlistptr)
 {
-    register ModulePtr       modptr, prevmodptr;
-    register struct ld_info  *ldiptr;
-    register char            *ldibuf;
-    register int             errflag, bufsize = 1024;
-    register unsigned int    offset;
+    ModulePtr       modptr, prevmodptr;
+    struct ld_info  *ldiptr;
+    char            *ldibuf;
+    int             errflag, bufsize = 1024;
+    unsigned int    offset;
     char *progname = Py_GetProgramName();
 
     /*
@@ -106,7 +106,7 @@
     char *message[1024], errbuf[1024];
     PyObject *pathname_ob = NULL;
     PyObject *errbuf_ob = NULL;
-    register int i,j;
+    int i,j;
 
     struct errtab {
         int errNo;
diff --git a/Python/marshal.c b/Python/marshal.c
index 1997e19..ec2d51f 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -613,7 +613,7 @@
 static int
 r_short(RFILE *p)
 {
-    register short x;
+    short x;
     unsigned char buffer[2];
 
     r_string((char *) buffer, 2, p);
@@ -627,7 +627,7 @@
 static long
 r_long(RFILE *p)
 {
-    register long x;
+    long x;
     unsigned char buffer[4];
 
     r_string((char *) buffer, 4, p);
diff --git a/Python/mystrtoul.c b/Python/mystrtoul.c
index 8a54cbf..725f07c 100644
--- a/Python/mystrtoul.c
+++ b/Python/mystrtoul.c
@@ -92,11 +92,11 @@
 **              exceptions - we don't check for them.
 */
 unsigned long
-PyOS_strtoul(register char *str, char **ptr, int base)
+PyOS_strtoul(char *str, char **ptr, int base)
 {
-    register unsigned long result = 0; /* return value of the function */
-    register int c;             /* current input character */
-    register int ovlimit;       /* required digits to overflow */
+    unsigned long result = 0; /* return value of the function */
+    int c;             /* current input character */
+    int ovlimit;       /* required digits to overflow */
 
     /* skip leading white space */
     while (*str && Py_ISSPACE(Py_CHARMASK(*str)))
@@ -213,7 +213,7 @@
         if (ovlimit > 0) /* no overflow check required */
             result = result * base + c;
         else { /* requires overflow check */
-            register unsigned long temp_result;
+            unsigned long temp_result;
 
             if (ovlimit < 0) /* guaranteed overflow */
                 goto overflowed;
diff --git a/Python/strdup.c b/Python/strdup.c
index 20187e0..769d3db 100644
--- a/Python/strdup.c
+++ b/Python/strdup.c
@@ -6,7 +6,7 @@
 strdup(const char *str)
 {
 	if (str != NULL) {
-		register char *copy = malloc(strlen(str) + 1);
+		char *copy = malloc(strlen(str) + 1);
 		if (copy != NULL)
 			return strcpy(copy, str);
 	}
diff --git a/Tools/unicode/makeunicodedata.py b/Tools/unicode/makeunicodedata.py
index 2f8e620..01021c8 100644
--- a/Tools/unicode/makeunicodedata.py
+++ b/Tools/unicode/makeunicodedata.py
@@ -552,7 +552,7 @@
     print("/* Returns 1 for Unicode characters having the bidirectional", file=fp)
     print(" * type 'WS', 'B' or 'S' or the category 'Zs', 0 otherwise.", file=fp)
     print(" */", file=fp)
-    print('int _PyUnicode_IsWhitespace(register const Py_UCS4 ch)', file=fp)
+    print('int _PyUnicode_IsWhitespace(const Py_UCS4 ch)', file=fp)
     print('{', file=fp)
     print('    switch (ch) {', file=fp)
 
@@ -570,7 +570,7 @@
     print(" * property 'BK', 'CR', 'LF' or 'NL' or having bidirectional", file=fp)
     print(" * type 'B', 0 otherwise.", file=fp)
     print(" */", file=fp)
-    print('int _PyUnicode_IsLinebreak(register const Py_UCS4 ch)', file=fp)
+    print('int _PyUnicode_IsLinebreak(const Py_UCS4 ch)', file=fp)
     print('{', file=fp)
     print('    switch (ch) {', file=fp)
     for codepoint in sorted(linebreaks):