Index: Lib/trace.py
===================================================================
--- Lib/trace.py	(revision 75305)
+++ Lib/trace.py	(working copy)
@@ -223,7 +223,8 @@
             try:
                 counts, calledfuncs, callers = \
                         pickle.load(open(self.infile, 'rb'))
-                self.update(self.__class__(counts, calledfuncs, callers))
+                self.update(self.__class__(counts, calledfuncs,
+                                           callers=callers))
             except (IOError, EOFError, ValueError), err:
                 print >> sys.stderr, ("Skipping counts file %r: %s"
                                       % (self.infile, err))