diff --git a/lib/constants.py b/lib/constants.py
index 9b1cd8c262e4a44f65aff98807e6b5b45630837f..d8d6022748632361f06120c120023b903329aa07 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -136,6 +136,8 @@ VALUE_DEFAULT = "default"
 VALUE_AUTO = "auto"
 VALUE_GENERATE = "generate"
 VALUE_NONE = "none"
+VALUE_TRUE = "true"
+VALUE_FALSE = "false"
 
 # hooks-related constants
 HOOKS_BASE_DIR = _autoconf.SYSCONFDIR + "/ganeti/hooks"