diff --git a/fsl/utils/settings.py b/fsl/utils/settings.py
index 7f011a1e87b9a42bb59f11cd1caba6e4b12f9765..fd28b7fcf19dbd68cda62370ec16cbcbb5f3856f 100644
--- a/fsl/utils/settings.py
+++ b/fsl/utils/settings.py
@@ -390,7 +390,7 @@ class Settings(object):
 
         try:
             with open(configFile, 'wb') as f:
-                pickle.dump(config, f)
+                pickle.dump(config, f, protocol=2)
         except (IOError, pickle.PicklingError, EOFError):
             log.warning('Unable to save {} configuration file '
                         '{}'.format(self.__configID, configFile),