diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index 923dd4fd8517e67ed8a245c97b4b7f018ff8944b..cbf39d0d7d1464496854200d1d5c4a2390194b0e 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -278,6 +278,7 @@ EOS
 check-run-command-as-root
 
 if [[ "$HOMEBREW_PREFIX" = "/usr/local" &&
+      "$HOMEBREW_PREFIX" != "$HOMEBREW_REPOSITORY" &&
       "$HOMEBREW_CELLAR" = "$HOMEBREW_REPOSITORY/Cellar" ]]
 then
   cat >&2 <<EOS