diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index d481f2a2d9..87471b0f08 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -671,7 +671,7 @@ module Homebrew
           # test no-op update from current commit (to current commit, a no-op).
           test "brew", "update-test", "--commit=HEAD"
         end
-      else
+      elsif @tap
         test "brew", "readall", "--aliases", @tap.name
       end
     end