diff --git a/setup.py b/setup.py
index 81da7775..7fb701da 100644
--- a/setup.py
+++ b/setup.py
@@ -90,6 +90,7 @@ Topic :: Software Development :: User Interfaces
 """
 
 DEPENDENCIES = [ 'six',
+                 'Pillow',
                  'PyPubSub']
 
 isWindows = sys.platform.startswith('win')