diff --git a/CHANGES b/CHANGES
index 8dd9041d..50bb8044 100644
--- a/CHANGES
+++ b/CHANGES
@@ -83,6 +83,9 @@
 
  * Fix mixed indentation for private methods. (Robin Dupret)
 
+ * Recalculate Content-Length even if hard coded if body is reset. Relevant
+   mostly for error handlers. (Nathan Esquenazi, Konstantin Haase)
+
  * Take views option into account for template caching. (Konstantin Haase)
 
 = 1.3.5 / 2013-02-25
diff --git a/lib/sinatra/base.rb b/lib/sinatra/base.rb
index ed5d4ebd..920eec4b 100644
--- a/lib/sinatra/base.rb
+++ b/lib/sinatra/base.rb
@@ -211,6 +211,7 @@ module Sinatra
         def block.each; yield(call) end
         response.body = block
       elsif value
+        headers.delete 'Content-Length' unless request.head?
         response.body = value
       else
         response.body