diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 3563badecc..337916a0aa 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -554,7 +554,7 @@ protected
       unless $?.success?
         unless ARGV.verbose?
           f.flush
-          Kernel.system "/usr/bin/tail -n 5 #{logfn}"
+          Kernel.system "/usr/bin/tail", "-n", "5", logfn
         end
         f.puts
         require 'cmd/--config'