diff --git a/krebs/3modules/power-action.nix b/krebs/3modules/power-action.nix
index 7227f4a9a..bb5b3e521 100644
--- a/krebs/3modules/power-action.nix
+++ b/krebs/3modules/power-action.nix
@@ -33,7 +33,7 @@ let
             description = ''
               check for charging status.
               null = don't care
-              true = only if system is charging
+              true = only if system is charging or unknown
               false = only if system is discharging
             '';
           };