diff --git a/bin/brew b/bin/brew
index e8473dbb35..c330831b6d 100755
--- a/bin/brew
+++ b/bin/brew
@@ -88,8 +88,8 @@ then
   PATH="/usr/bin:/bin:/usr/sbin:/sbin"
 
   FILTERED_ENV=()
-  for VAR in HOME SHELL PATH TERM LOGNAME USER CI TRAVIS SUDO_ASKPASS
-             http_proxy HTTPS_PROXY FTP_PROXY \
+  for VAR in HOME SHELL PATH TERM LOGNAME USER CI TRAVIS SUDO_ASKPASS \
+             http_proxy https_proxy ftp_proxy HTTPS_PROXY FTP_PROXY \
              "${!HOMEBREW_@}" "${!TRAVIS_@}" "${!JENKINS_@}"
   do
     # Skip if variable value is empty.