diff --git a/xbob/example/faceverify/dct_ubm.py b/xbob/example/faceverify/dct_ubm.py
index 2cd143e3d8060254c21d71e3aa5f98a3eb426efd..d72d597226c2f118e14e47d8440c1d9d74a08f6a 100644
--- a/xbob/example/faceverify/dct_ubm.py
+++ b/xbob/example/faceverify/dct_ubm.py
@@ -23,6 +23,8 @@ import bob
 import xbob.db.atnt
 import os, sys
 import numpy
+import matplotlib
+matplotlib.use('pdf')
 from matplotlib import pyplot
 
 from .utils import atnt_database_directory
diff --git a/xbob/example/faceverify/eigenface.py b/xbob/example/faceverify/eigenface.py
index fc58c3d444780cae06f8a29714c51bfb95e96607..c412e7c9f650543f3f93c00eea7ab198aa1734fd 100644
--- a/xbob/example/faceverify/eigenface.py
+++ b/xbob/example/faceverify/eigenface.py
@@ -23,6 +23,8 @@ import bob
 import xbob.db.atnt
 import os, sys
 import numpy, scipy.spatial
+import matplotlib
+matplotlib.use('pdf')
 from matplotlib import pyplot
 
 from .utils import atnt_database_directory
diff --git a/xbob/example/faceverify/gabor_graph.py b/xbob/example/faceverify/gabor_graph.py
index 8a4d35f04413ce1217bd853f72e5f033e28af956..4f6f516eec5566fa268548e3d3996e4b6ef93b02 100644
--- a/xbob/example/faceverify/gabor_graph.py
+++ b/xbob/example/faceverify/gabor_graph.py
@@ -23,6 +23,8 @@ import bob
 import xbob.db.atnt
 import os, sys
 import numpy, math
+import matplotlib
+matplotlib.use('pdf')
 from matplotlib import pyplot
 
 from .utils import atnt_database_directory