diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index ba6592eba5..d373039c34 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -235,6 +235,7 @@ export HOMEBREW_MACOS_VERSION
 export HOMEBREW_MACOS_VERSION_NUMERIC
 export HOMEBREW_USER_AGENT
 export HOMEBREW_USER_AGENT_CURL
+export HOMEBREW_BOTTLE_DEFAULT_DOMAIN
 
 if [[ -n "$HOMEBREW_MACOS" && -x "/usr/bin/xcode-select" ]]
 then