diff --git a/Library/Homebrew/test/test_formula_install.rb b/Library/Homebrew/test/test_formula_install.rb
index 10520a7bd4..00fc1da6ba 100644
--- a/Library/Homebrew/test/test_formula_install.rb
+++ b/Library/Homebrew/test/test_formula_install.rb
@@ -35,9 +35,8 @@ class InstallTests < Homebrew::TestCase
       assert_predicate f.bin, :directory?
       assert_equal 3, f.bin.children.length
 
-      libexec = f.prefix+'libexec'
-      assert_predicate libexec, :directory?
-      assert_equal 1, libexec.children.length
+      assert_predicate f.libexec, :directory?
+      assert_equal 1, f.libexec.children.length
 
       refute_predicate f.prefix+'main.c', :exist?
       assert_predicate f, :installed?