diff --git a/demos/web/server.py b/demos/web/server.py
index e8958df..2b19640 100755
--- a/demos/web/server.py
+++ b/demos/web/server.py
@@ -40,6 +40,8 @@ from sklearn.grid_search import GridSearchCV
 from sklearn.manifold import TSNE
 from sklearn.svm import SVC
 
+import matplotlib as mpl
+mpl.use('Agg')
 import matplotlib.pyplot as plt
 import matplotlib.cm as cm