diff --git a/skimage/measure/tests/test_marching_cubes.py b/skimage/measure/tests/test_marching_cubes.py
index a9d59a21..5cce3ea8 100644
--- a/skimage/measure/tests/test_marching_cubes.py
+++ b/skimage/measure/tests/test_marching_cubes.py
@@ -8,30 +8,32 @@ from skimage.measure import (marching_cubes,
                              mesh_surface_area, correct_mesh_orientation)
 from skimage.measure._marching_cubes_lewiner import _expected_output_args
 
+def func_that_knows_about_its_outputs(r):
+    # Must be defined in global scope to avoid syntax error on Python 2 *sigh*
+    nout = _expected_output_args()
+    print(nout)
+    r.append(nout)
+    return [nout] * int(nout)
+
 
 def test_expected_output_args():
     
+    foo = func_that_knows_about_its_outputs
+    
     res = []
-    
-    def foo():
-        nout = _expected_output_args()
-        print(nout)
-        res.append(nout)
-        return [nout] * int(nout)
-    
-    foo()
-    a = foo()
-    a, b = foo()
-    a, b, c = foo()
+    foo(res)
+    a = foo(res)
+    a, b = foo(res)
+    a, b, c = foo(res)
     assert res == [0, 1, 2, 3] or res == [0, 0, 2, 3]
     # ``a = foo()`` somehow yields 0 in test, which is ok for us;
     # we only want to distinguish between > 2 args or not
     
     if sys.version_info >= (3, 3):
         res = []
-        exec('*a, b, c = foo()')
-        exec('a, b, c, *d = foo()')
-        exec('a, b, *c, d, e = foo()')
+        exec('*a, b, c = foo(res)')
+        exec('a, b, c, *d = foo(res)')
+        exec('a, b, *c, d, e = foo(res)')
         assert res == [2.1, 3.1, 4.1]