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;