diff --git a/bin/brew b/bin/brew
index 30e1fec5f2..bdbaac8ae9 100755
--- a/bin/brew
+++ b/bin/brew
@@ -75,7 +75,7 @@ HOMEBREW_LIBRARY="${HOMEBREW_REPOSITORY}/Library"
 
 # Copy and export all HOMEBREW_* variables previously mentioned in
 # manpage or used elsewhere by Homebrew.
-for VAR in BAT_THEME BROWSER DISPLAY EDITOR NO_COLOR TMUX DBUS_SESSION_BUS_ADDRESS
+for VAR in BAT_THEME BROWSER DISPLAY EDITOR NO_COLOR TMUX DBUS_SESSION_BUS_ADDRESS XDG_RUNTIME_DIR
 do
   # Skip if variable value is empty.
   [[ -z "${!VAR}" ]] && continue