diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index 7feeac9f23..9c4326f309 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -576,7 +576,7 @@ fi
 
 if [[ -z "$HOMEBREW_RUBY_WARNINGS" ]]
 then
-  export HOMEBREW_RUBY_WARNINGS="-W0"
+  export HOMEBREW_RUBY_WARNINGS="-W1"
 fi
 
 if [[ -z "$HOMEBREW_BOTTLE_DOMAIN" ]]