diff --git a/tests/11-vacuum/__init__.py b/tests/11-vacuum/__init__.py
index a323b4d..3d79d94 100644
--- a/tests/11-vacuum/__init__.py
+++ b/tests/11-vacuum/__init__.py
@@ -140,7 +140,8 @@ class Test(GrayTest, TestCase):
             plt.tricontourf(data['x'], data['y'],
                             abs(S_true.real - S_gray.real),
                             levels=8, cmap='summer')
-            plt.colorbar()
+            cbar = plt.colorbar()
+            cbar.ax.ticklabel_format(scilimits=[0, 0], useMathText=True)
             plt.scatter(data['x'], data['y'], c='k', s=5)
 
             plt.subplot(122, aspect='equal')
@@ -151,7 +152,8 @@ class Test(GrayTest, TestCase):
             plt.tricontourf(data['x'], data['y'],
                             abs(S_true.imag - S_gray.imag),
                             levels=8, cmap='summer')
-            plt.colorbar()
+            cbar = plt.colorbar()
+            cbar.ax.ticklabel_format(scilimits=[0, 0], useMathText=True)
             plt.scatter(data['x'], data['y'], c='k', s=5)
             plt.show()