diff --git a/bin/brew b/bin/brew
index 5831791a75..5206997402 100755
--- a/bin/brew
+++ b/bin/brew
@@ -88,7 +88,7 @@ then
 
   FILTERED_ENV=()
   # Filter all but the specific variables.
-  for VAR in HOME SHELL PATH TERM TERMINFO COLUMNS LOGNAME USER CI SSH_AUTH_SOCK SUDO_ASKPASS \
+  for VAR in HOME SHELL PATH TERM TERMINFO COLUMNS DISPLAY LOGNAME USER CI SSH_AUTH_SOCK SUDO_ASKPASS \
              http_proxy https_proxy ftp_proxy no_proxy all_proxy HTTPS_PROXY FTP_PROXY ALL_PROXY \
              "${!HOMEBREW_@}" "${!TRAVIS_@}"
   do