diff --git a/lib/constants.py b/lib/constants.py
index 8cb675fd02cff16c9b0031494b30065d8cfc3f52..f9834f568435efbfb4ccc881a69ca8386167259e 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -25,7 +25,7 @@ from ganeti import _autoconf
 
 # various versions
 CONFIG_VERSION = 3
-PROTOCOL_VERSION = 5
+PROTOCOL_VERSION = 6
 RELEASE_VERSION = _autoconf.PACKAGE_VERSION
 OS_API_VERSION = 5
 EXPORT_VERSION = 0