diff -r 2a18f6b85da2 Python/ceval.c
--- a/Python/ceval.c	Sun Apr 12 18:47:56 2015 -0400
+++ b/Python/ceval.c	Tue Apr 14 12:34:49 2015 -0700
@@ -3826,8 +3826,9 @@
             /* Iterator done, via error or exhaustion. */
             if (!PyErr_Occurred()) {
                 PyErr_Format(PyExc_ValueError,
-                    "need more than %d value%s to unpack",
-                    i, i == 1 ? "" : "s");
+                    "need more than %d value%s to unpack "
+                    "(expected %d)",
+                    i, i == 1 ? "" : "s", argcnt);
             }
             goto Error;
         }