diff --git a/execjs.gemspec b/execjs.gemspec
index 17f3009..2f228b5 100644
--- a/execjs.gemspec
+++ b/execjs.gemspec
@@ -1,4 +1,5 @@
-require File.expand_path("../lib/execjs/version.rb", __FILE__)
+$:.unshift File.expand_path('..', __FILE__)
+require 'execjs/version'
 
 Gem::Specification.new do |s|
   s.name    = "execjs"
diff --git a/lib/execjs/johnson_runtime.rb b/lib/execjs/johnson_runtime.rb
index 1d3e1ff..44a9dae 100644
--- a/lib/execjs/johnson_runtime.rb
+++ b/lib/execjs/johnson_runtime.rb
@@ -7,7 +7,7 @@ module ExecJS
       end
 
       def exec(source, options = {})
-        souce = source.encode('UTF-8') if source.respond_to?(:encode)
+        source = source.encode('UTF-8') if source.respond_to?(:encode)
 
         if /\S/ =~ source
           eval "(function(){#{source}})()", options
@@ -15,7 +15,7 @@ module ExecJS
       end
 
       def eval(source, options = {})
-        souce = source.encode('UTF-8') if source.respond_to?(:encode)
+        source = source.encode('UTF-8') if source.respond_to?(:encode)
 
         if /\S/ =~ source
           unbox @runtime.evaluate("(#{source})")
diff --git a/lib/execjs/ruby_rhino_runtime.rb b/lib/execjs/ruby_rhino_runtime.rb
index b971bd6..e6d5f8a 100644
--- a/lib/execjs/ruby_rhino_runtime.rb
+++ b/lib/execjs/ruby_rhino_runtime.rb
@@ -42,14 +42,21 @@ module ExecJS
       end
 
       def unbox(value)
-        case value
+        case value = ::Rhino::To.ruby(value)
         when ::Rhino::NativeFunction
           nil
         when ::Rhino::NativeObject
           value.inject({}) do |vs, (k, v)|
-            vs[k] = unbox(v) unless v.is_a?(::Rhino::NativeFunction)
+            case v
+            when ::Rhino::NativeFunction, ::Rhino::J::Function
+              nil
+            else
+              vs[k] = unbox(v)
+            end
             vs
           end
+        when Array
+          value.map { |v| unbox(v) }
         else
           value
         end
diff --git a/test/test_runtime.rb b/test/test_runtime.rb
index 20ee2f2..2e65f0a 100644
--- a/test/test_runtime.rb
+++ b/test/test_runtime.rb
@@ -30,8 +30,10 @@ class TestRuntime < Test::Unit::TestCase
     assert_equal 0, @runtime.eval("0")
     assert_equal true, @runtime.eval("true")
     assert_equal [1, 2], @runtime.eval("[1, 2]")
+    assert_equal [1, nil], @runtime.eval("[1, function() {}]")
     assert_equal "hello", @runtime.eval("'hello'")
     assert_equal({"a"=>1,"b"=>2}, @runtime.eval("{a:1,b:2}"))
+    assert_equal({"a"=>true}, @runtime.eval("{a:true,b:function (){}}"))
     assert_equal "café", @runtime.eval("'café'")
     assert_equal "☃", @runtime.eval('"☃"')
     assert_equal "☃", @runtime.eval('"\u2603"')