diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index ada877baa797240700ae31ec6209bde3f6a1aa2e..edbc8db0593a7fb18beeff08307a1c1d655c9c48 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -235,6 +235,9 @@ update-preinstall() {
   then
     brew update --preinstall
   fi
+
+  # If we've checked for updates, we don't need to check again.
+  export HOMEBREW_NO_AUTO_UPDATE="1"
 }
 
 if [[ -n "$HOMEBREW_BASH_COMMAND" ]]
diff --git a/Library/Homebrew/cmd/update.sh b/Library/Homebrew/cmd/update.sh
index 2e40d1d428352d6e8fb1052ace9bd97a50ff1b8a..3fa5ba1fb6d28bece214a1c709b2ab50f7a8a3ed 100644
--- a/Library/Homebrew/cmd/update.sh
+++ b/Library/Homebrew/cmd/update.sh
@@ -359,8 +359,6 @@ EOS
 
   # only allow one instance of brew update
   lock update
-  # prevent recursive updates
-  export HOMEBREW_NO_AUTO_UPDATE="1"
 
   git_init_if_necessary
   # rename Taps directories
diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index 94775e98d8857663226485847ce8de06dda69c51..e3ba7e41ef95ff6e33ea970b85eea252dca78bcd 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -920,7 +920,6 @@ module Homebrew
     end
 
     ENV["HOMEBREW_DEVELOPER"] = "1"
-    ENV["HOMEBREW_NO_AUTO_UPDATE"] = "1"
     ENV["HOMEBREW_SANDBOX"] = "1"
     ENV["HOMEBREW_RUBY_MACHO"] = "1" if RUBY_TWO
     ENV["HOMEBREW_NO_EMOJI"] = "1"