Index: Objects/fileobject.c
===================================================================
--- Objects/fileobject.c	(revision 74264)
+++ Objects/fileobject.c	(working copy)
@@ -324,7 +324,7 @@
 	assert(f->f_fp == NULL);
 
 	/* probably need to replace 'U' by 'rb' */
-	newmode = PyMem_MALLOC(strlen(mode) + 3);
+	newmode = PyMem_MALLOC(3 + strlen(mode));
 	if (!newmode) {
 		PyErr_NoMemory();
 		return NULL;