diff --git a/Library/Homebrew/test/test_build_environment.rb b/Library/Homebrew/test/test_build_environment.rb
index d560f29152..dff58f4206 100644
--- a/Library/Homebrew/test/test_build_environment.rb
+++ b/Library/Homebrew/test/test_build_environment.rb
@@ -29,9 +29,8 @@ class BuildEnvironmentTests < Homebrew::TestCase
 
   def test_marshal
     @env << :userpaths
-    @env << Proc.new { 1 }
-    dump = Marshal.dump(@env)
-    assert_predicate Marshal.load(dump), :userpaths?
+    @env.proc = Proc.new {}
+    assert_predicate Marshal.load(Marshal.dump(@env)), :userpaths?
   end
 
   def test_env_block