diff --git a/tfmpl/samples/sgd.py b/tfmpl/samples/sgd.py
index 562e6e4..47f96ce 100644
--- a/tfmpl/samples/sgd.py
+++ b/tfmpl/samples/sgd.py
@@ -20,7 +20,7 @@
 
         def beale(x, y):
             '''Beale surface for optimization tests.'''
-            with tf.name_scope('beale', [x, y]):
+            with tf.name_scope('beale', values=[x, y]):
                 return (1.5 - x + x*y)**2 + (2.25 - x + x*y**2)**2 + (2.625 - x + x*y**3)**2
 
         # List of optimizers to compare
@@ -102,4 +102,4 @@ def draw(xy, z):
                 summary = sess.run(all_summaries)
                 writer.add_summary(summary, global_step=i)
                 writer.flush()
-            sess.run(train)
\ No newline at end of file
+            sess.run(train)