diff --git a/lib/backend.py b/lib/backend.py
index b08c93739ea12f498ebc7f9f36a1d964788a6676..d438f1a934f9bd53f6e929e6d1c1c32bb39a1e40 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -958,9 +958,10 @@ def InstanceReboot(instance, reboot_type):
         instance OS, do not recreate the VM
       - L{constants.INSTANCE_REBOOT_HARD}: tear down and
         restart the VM (at the hypervisor level)
-      - the other reboot type (L{constants.INSTANCE_REBOOT_HARD})
-        is not accepted here, since that mode is handled
-        differently
+      - the other reboot type (L{constants.INSTANCE_REBOOT_FULL}) is
+        not accepted here, since that mode is handled differently, in
+        cmdlib, and translates into full stop and start of the
+        instance (instead of a call_instance_reboot RPC)
   @rtype: boolean
   @return: the success of the operation