diff --git a/Library/Homebrew/dev-cmd/edit.rb b/Library/Homebrew/dev-cmd/edit.rb
index 26be25488d..9164c553d7 100644
--- a/Library/Homebrew/dev-cmd/edit.rb
+++ b/Library/Homebrew/dev-cmd/edit.rb
@@ -28,6 +28,8 @@ module Homebrew
       sig { override.void }
       def run
         ENV["COLORTERM"] = ENV.fetch("HOMEBREW_COLORTERM", nil)
+        # Recover $TMPDIR for emacsclient
+        ENV["TMPDIR"] = ENV.fetch("HOMEBREW_TMPDIR", nil)
 
         unless (HOMEBREW_REPOSITORY/".git").directory?
           odie <<~EOS
diff --git a/bin/brew b/bin/brew
index 5c527f632d..58bc4f24a3 100755
--- a/bin/brew
+++ b/bin/brew
@@ -193,6 +193,7 @@ USED_BY_HOMEBREW_VARS=(
   RBENV_ROOT
   SSH_TTY
   SUDO_USER
+  TMPDIR
   TMUX
   XDG_CACHE_HOME
   XDG_DATA_DIRS