diff -r ee9921b29fd8 Python/ceval.c
--- a/Python/ceval.c	Mon Apr 18 21:21:10 2016 +0300
+++ b/Python/ceval.c	Tue Apr 19 12:13:49 2016 -0400
@@ -4890,6 +4890,21 @@
 {
     PyObject *callargs, *w;
 
+    if (!nstack) {
+        if (!stararg) {
+            /* There are no positional arguments on the stack and there is no
+               sequence to be unpacked. */
+            return PyTuple_New(0);
+        }
+        if (PyTuple_CheckExact(stararg)) {
+            /* No arguments are passed on the stack and the sequence is not a
+               tuple subclass so we can just pass the stararg tuple directly
+               to the function. */
+            Py_INCREF(stararg);
+            return stararg;
+        }
+    }
+
     callargs = PyTuple_New(nstack + nstar);
     if (callargs == NULL) {
         return NULL;