diff -r 4d4277941a45 Lib/test/test_sys_settrace.py
--- a/Lib/test/test_sys_settrace.py	Fri Apr 12 23:30:59 2013 +0300
+++ b/Lib/test/test_sys_settrace.py	Sat Apr 13 19:18:19 2013 -0400
@@ -458,6 +458,26 @@
             self.fail("exception not propagated")
 
 
+    def test_exception_arguments(self):
+        def f():
+            x = 5
+            # this should raise an error
+            x.no_such_attr
+        def g(frame, event, arg):
+            if (event == 'exception'):
+                type, exception, trace = arg
+                if not isinstance(exception, Exception):
+                    self.fail("arg should be an instance of exception")
+            return g
+
+        sys.settrace(g)
+        try:
+            f()
+        except AttributeError:
+            # this is expected
+            pass
+
+
 # 'Jump' tests: assigning to frame.f_lineno within a trace function
 # moves the execution position - it's how debuggers implement a Jump
 # command (aka. "Set next statement").
diff -r 4d4277941a45 Misc/ACKS
--- a/Misc/ACKS	Fri Apr 12 23:30:59 2013 +0300
+++ b/Misc/ACKS	Sat Apr 13 19:18:19 2013 -0400
@@ -211,6 +211,7 @@
 Nicolas Chauvat
 Jerry Chen
 Michael Chermside
+Ingrid Cheung
 Albert Chin-A-Young
 Adal Chiriliuc
 Matt Chisholm
@@ -802,6 +803,7 @@
 Greg McFarlane
 Alan McIntyre
 Michael McLay
+Brendan McLoughlin
 Mark Mc Mahon
 Gordon McMillan
 Andrew McNamara
diff -r 4d4277941a45 Python/ceval.c
--- a/Python/ceval.c	Fri Apr 12 23:30:59 2013 +0300
+++ b/Python/ceval.c	Sat Apr 13 19:18:19 2013 -0400
@@ -3793,6 +3793,7 @@
         value = Py_None;
         Py_INCREF(value);
     }
+    PyErr_NormalizeException(&type, &value, &traceback);
     arg = PyTuple_Pack(3, type, value, traceback);
     if (arg == NULL) {
         PyErr_Restore(type, value, traceback);