diff --git a/Objects/listobject.c b/Objects/listobject.c
index 9c49dad..e85e2f4 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -563,7 +563,7 @@
 	if (!b)
 		return NULL;
 
-	if (PyObject_Length(b) == 0)
+	if (PyObject_Size(b) == 0)
 		/* short circuit when b is empty */
 		goto ok;
 
@@ -585,7 +585,7 @@
 		}
 	}
 
-	blen = PyObject_Length(b);
+	blen = PyObject_Size(b);
 
 	/* resize a using idiom */
 	items = self->ob_item;
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index f4b90e8..ab44e91 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -759,7 +759,7 @@
 	/* From here on out, errors go through finally: for proper
 	 * reference count manipulations.
 	 */
-	seqlen = PySequence_Length(seq);
+	seqlen = PySequence_Size(seq);
 	if (seqlen == 1) {
 		item = PySequence_Fast_GET_ITEM(seq, 0);
 		Py_INCREF(item);
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index f10b800..02d1b0d 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -2650,7 +2650,7 @@
     int sz = 100;
     int i;
 
-    seqlen = PySequence_Length(seq);
+    seqlen = PySequence_Size(seq);
     if (seqlen < 0 && PyErr_Occurred())
 	return NULL;