diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index a5b7331d3777..6c1f7a2c4019 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -2996,24 +2996,21 @@ def test_hist_stacked_step():
     ax.hist((d1, d2), histtype="step", stacked=True)
 
 
-@image_comparison(baseline_images=['hist_stacked_normed'])
-def test_hist_stacked_normed():
-    # make some data
-    d1 = np.linspace(1, 3, 20)
-    d2 = np.linspace(0, 10, 50)
-    fig, ax = plt.subplots()
-    with pytest.warns(UserWarning):
-        ax.hist((d1, d2), stacked=True, normed=True)
-
-
-@image_comparison(baseline_images=['hist_stacked_normed'], extensions=['png'])
+@image_comparison(baseline_images=['hist_stacked_normed',
+                                   'hist_stacked_normed'])
 def test_hist_stacked_density():
     # make some data
     d1 = np.linspace(1, 3, 20)
     d2 = np.linspace(0, 10, 50)
+
     fig, ax = plt.subplots()
     ax.hist((d1, d2), stacked=True, density=True)
 
+    # Also check that the old keyword works.
+    fig, ax = plt.subplots()
+    with pytest.warns(UserWarning):
+        ax.hist((d1, d2), stacked=True, normed=True)
+
 
 @pytest.mark.parametrize('normed', [False, True])
 @pytest.mark.parametrize('density', [False, True])