diff --git a/internal/p10k.zsh b/internal/p10k.zsh
index 9ba33a78..ac9e3bc9 100644
--- a/internal/p10k.zsh
+++ b/internal/p10k.zsh
@@ -1312,6 +1312,7 @@ _p9k_prompt_battery_set_args() {
     ;;
 
     Linux|Android)
+      # See https://sourceforge.net/projects/acpiclient.
       local -a bats=( /sys/class/power_supply/(BAT*|battery)/(FN) )
       (( $#bats )) || return