diff -r 1fed50c8ea62 Modules/_elementtree.c
--- a/Modules/_elementtree.c	Tue Nov 26 10:46:06 2013 +0100
+++ b/Modules/_elementtree.c	Wed Nov 27 23:17:01 2013 +0100
@@ -3038,7 +3038,10 @@
     if (PyErr_Occurred())
         return;
 
-    suri = PyUnicode_DecodeUTF8(uri, strlen(uri), "strict");
+    if (uri)
+        suri = PyUnicode_DecodeUTF8(uri, strlen(uri), "strict");
+    else
+        sprefix = PyUnicode_FromString("");
     if (!suri)
         return;