1 files changed, 1 insertions, 1 deletions
diff --git a/SendGrid/SendGrid/IHeader.cs b/SendGrid/SendGrid/IHeader.cs
index 640d985..6756ed5 100755
--- a/SendGrid/SendGrid/IHeader.cs
+++ b/SendGrid/SendGrid/IHeader.cs
@@ -16,6 +16,6 @@ namespace SendGrid
         void Disable(String filter);
         void AddFilterSetting(String filter, IEnumerable<String> settings, String value);
         void AddHeader(MailMessage mime);
-        void AsJson();
+        String AsJson();
     }
 }