diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 5b20ab3..45e3c49 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -255,6 +255,10 @@
 d22v(*(1, 2, 3, 4))
 d22v(1, 2, *(3, 4, 5))
 d22v(1, *(2, 3), **{'d': 4})
+def d31v((x)): pass
+d31v(1)
+def d32v((x,)): pass
+d32v((1,))
 
 ### lambdef: 'lambda' [varargslist] ':' test
 print 'lambdef'
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index ce346b9..79be369 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -304,10 +304,12 @@
         self.assertArgSpecEquals(A.m, ['self'])
 
     def test_getargspec_sublistofone(self):
-        def sublistOfOne((foo)): return 1
-
+        def sublistOfOne((foo,)): return 1
         self.assertArgSpecEquals(sublistOfOne, [['foo']])
 
+        def fakeSublistOfOne((foo)): return 1
+        self.assertArgSpecEquals(fakeSublistOfOne, ['foo'])
+
     def test_classify_oldstyle(self):
         class A:
             def s(): pass
diff --git a/Python/ast.c b/Python/ast.c
index 30275a6..86f3d3c 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -645,10 +645,17 @@
 		    goto error;
 		}
                 if (NCH(ch) == 3) {
-                    asdl_seq_SET(args, k++, 
-                                    compiler_complex_args(c, CHILD(ch, 1))); 
-		}
-                else if (TYPE(CHILD(ch, 0)) == NAME) {
+		    ch = CHILD(ch, 1);
+		    /* def foo((x)): is not complex, special case. */
+		    if (NCH(ch) != 1) {
+			/* We have complex arguments, setup for unpacking. */
+			asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
+		    } else {
+			/* def foo((x)): setup for checking NAME below. */
+			ch = CHILD(ch, 0);
+		    }
+                }
+                if (TYPE(CHILD(ch, 0)) == NAME) {
 		    expr_ty name;
 		    if (!strcmp(STR(CHILD(ch, 0)), "None")) {
 			    ast_error(CHILD(ch, 0), "assignment to None");