diff --git a/CHANGES b/CHANGES
index c1055b29..aefd0b61 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,10 @@
  * No longer include Sinatra::Delegator in Object, instead extend the main
    object only. (Konstantin Haase)
 
+ * Exception#code is only used when :use_code is enabled and displays a warning.
+   Moreover, it will be ignored if the value is not between 400 and 599. You
+   should use Exception#http_status instead. (Konstantin Haase)
+
 = 1.3.2 / 2011-12-30
 
  * Don't automatically add `Rack::CommonLogger` if `Rack::Server` is adding it,
diff --git a/lib/sinatra/base.rb b/lib/sinatra/base.rb
index 893016ef..9731ef3c 100644
--- a/lib/sinatra/base.rb
+++ b/lib/sinatra/base.rb
@@ -88,7 +88,7 @@ module Sinatra
   end
 
   class NotFound < NameError #:nodoc:
-    def code ; 404 ; end
+    def http_status; 404 end
   end
 
   # Methods available to routes, before/after filters, and views.
@@ -893,7 +893,19 @@ module Sinatra
     # Error handling during requests.
     def handle_exception!(boom)
       @env['sinatra.error'] = boom
-      status boom.respond_to?(:code) ? Integer(boom.code) : 500
+
+      if boom.respond_to? :http_status
+        status(boom.http_status)
+      elsif settings.use_code? and boom.respond_to? :code and boom.code.between? 400, 599
+        status(boom.code)
+        warn "Using #{boom.class}#code (#{status}) for setting status code. This is deprecated. " \
+          "Use #http_status instead. If this happens unintentional, please \`disable :use_code\`" \
+          " in your application."
+      else
+        status(500)
+      end
+
+      status(500) unless status.between? 400, 599
 
       if server_error?
         dump_errors! boom if settings.dump_errors?
@@ -1491,6 +1503,7 @@ module Sinatra
     set :logging, false
     set :protection, true
     set :method_override, false
+    set :use_code, true
     set :default_encoding, "utf-8"
     set :add_charset, %w[javascript xml xhtml+xml json].map { |t| "application/#{t}" }
     settings.add_charset << /^text\//
diff --git a/test/mapped_error_test.rb b/test/mapped_error_test.rb
index 0a16af73..5a96da03 100644
--- a/test/mapped_error_test.rb
+++ b/test/mapped_error_test.rb
@@ -7,9 +7,14 @@ class FooNotFound < Sinatra::NotFound
 end
 
 class FooSpecialError < RuntimeError
-  def code; 501 end
+  def http_status; 501 end
 end
 
+class FooStatusOutOfRangeError < RuntimeError
+  def code; 4000 end
+end
+
+
 class MappedErrorTest < Test::Unit::TestCase
   def test_default
     assert true
@@ -182,7 +187,7 @@ class MappedErrorTest < Test::Unit::TestCase
       assert_equal 'subclass', body
     end
 
-    it 'honors Exception#code if present' do
+    it 'honors Exception#http_status if present' do
       mock_app do
         set :raise_errors, false
         error(501) { 'Foo!' }
@@ -192,6 +197,16 @@ class MappedErrorTest < Test::Unit::TestCase
       assert_equal 501, status
       assert_equal 'Foo!', body
     end
+
+    it 'does not rely on Exception#code for invalid codes' do
+      mock_app do
+        set :raise_errors, false
+        get('/') { raise FooStatusOutOfRangeError }
+      end
+      get '/'
+      assert_equal 500, status
+    end
+
   end
 
   describe 'Custom Error Pages' do