diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 31db95f..25f7763 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -102,7 +102,7 @@
             memcpy(new->ob_bytes, bytes, size);
         new->ob_bytes[size] = '\0';  /* Trailing null byte */
     }
-    new->ob_size = size;
+    Py_Size(new) = size;
     new->ob_alloc = alloc;
 
     return (PyObject *)new;
@@ -232,7 +232,7 @@
         return PyErr_NoMemory();
     if (size < self->ob_alloc) {
         Py_Size(self) = size;
-	self->ob_bytes[self->ob_size] = '\0'; /* Trailing null byte */
+	self->ob_bytes[Py_Size(self)] = '\0'; /* Trailing null byte */
     }
     else if (PyBytes_Resize((PyObject *)self, size) < 0)
         return NULL;
@@ -281,7 +281,7 @@
         return PyErr_NoMemory();
     if (size < self->ob_alloc) {
         Py_Size(self) = size;
-	self->ob_bytes[self->ob_size] = '\0'; /* Trailing null byte */
+	self->ob_bytes[Py_Size(self)] = '\0'; /* Trailing null byte */
     }
     else if (PyBytes_Resize((PyObject *)self, size) < 0)
         return NULL;
@@ -816,7 +816,7 @@
 bytes_repr(PyBytesObject *self)
 {
     static const char *hexdigits = "0123456789abcdef";
-    size_t newsize = 3 + 4 * self->ob_size;
+    size_t newsize = 3 + 4 * Py_Size(self);
     PyObject *v;
     if (newsize > PY_SSIZE_T_MAX || newsize / 4 != Py_Size(self)) {
         PyErr_SetString(PyExc_OverflowError,
@@ -2594,7 +2594,7 @@
 bytes_join(PyBytesObject *self, PyObject *it)
 {
     PyObject *seq;
-    Py_ssize_t mysize = self->ob_size;
+    Py_ssize_t mysize = Py_Size(self);
     Py_ssize_t i;
     Py_ssize_t n;
     PyObject **items;
@@ -2727,7 +2727,7 @@
     return Py_BuildValue("(O(s#s))",
                          Py_Type(self),
                          self->ob_bytes == NULL ? "" : self->ob_bytes,
-                         self->ob_size,
+                         Py_Size(self),
                          "latin-1");
 }
 
diff --git a/Objects/setobject.c b/Objects/setobject.c
index cc60488..a5366c8 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -619,21 +619,21 @@
 	if (status != 0) {
 		if (status < 0)
 			return NULL;
-		return PyUnicode_FromFormat("%s(...)", so->ob_type->tp_name);
+		return PyUnicode_FromFormat("%s(...)", Py_Type(so)->tp_name);
 	}
 
 	/* shortcut for the empty set */
 	if (!so->used) {
 		Py_ReprLeave((PyObject*)so);
-		return PyUnicode_FromFormat("%s()", so->ob_type->tp_name);
+		return PyUnicode_FromFormat("%s()", Py_Type(so)->tp_name);
 	}
 
 	keys = PySequence_List((PyObject *)so);
 	if (keys == NULL)
 		goto done;
 
-	if (so->ob_type != &PySet_Type) {
-		result = PyUnicode_FromFormat("%s(%R)", so->ob_type->tp_name, keys);
+	if (Py_Type(so) != &PySet_Type) {
+		result = PyUnicode_FromFormat("%s(%R)", Py_Type(so)->tp_name, keys);
 		Py_DECREF(keys);
 	}
 	else {
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 6156b2f..68dfd35 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -835,7 +835,7 @@
 	static const char *hexdigits = "0123456789abcdef";
 	register PyStringObject* op = (PyStringObject*) obj;
 	Py_ssize_t length = PyString_GET_SIZE(op);
-	size_t newsize = 3 + 4 * op->ob_size;
+	size_t newsize = 3 + 4 * Py_Size(op);
 	PyObject *v;
 	if (newsize > PY_SSIZE_T_MAX || newsize / 4 != Py_Size(op)) {
 		PyErr_SetString(PyExc_OverflowError,
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index bf031bb..6944eab 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -305,7 +305,7 @@
 
         case SSTATE_INTERNED_MORTAL:
             /* revive dead object temporarily for DelItem */
-            unicode->ob_refcnt = 3;
+            Py_Refcnt(unicode) = 3;
             if (PyDict_DelItem(interned, (PyObject *)unicode) != 0)
                 Py_FatalError(
                     "deletion of interned unicode string failed");
@@ -8758,7 +8758,7 @@
 	PyThreadState_GET()->recursion_critical = 0;
 	/* The two references in interned are not counted by refcnt.
 	   The deallocator will take care of this */
-	s->ob_refcnt -= 2;
+	Py_Refcnt(s) -= 2;
 	PyUnicode_CHECK_INTERNED(s) = SSTATE_INTERNED_MORTAL;
 }
 
@@ -8812,11 +8812,11 @@
 			/* XXX Shouldn't happen */
 			break;
 		case SSTATE_INTERNED_IMMORTAL:
-			s->ob_refcnt += 1;
+			Py_Refcnt(s) += 1;
 			immortal_size += s->length;
 			break;
 		case SSTATE_INTERNED_MORTAL:
-			s->ob_refcnt += 2;
+			Py_Refcnt(s) += 2;
 			mortal_size += s->length;
 			break;
 		default: