diff --git a/lib/bindings/http/unmarshaller_0_2.js b/lib/bindings/http/unmarshaller_0_2.js
index 31cf543..49fc02f 100644
--- a/lib/bindings/http/unmarshaller_0_2.js
+++ b/lib/bindings/http/unmarshaller_0_2.js
@@ -1,10 +1,8 @@
 var Spec02 = require("../../specs/spec_0_2.js");
 var JSONParser = require("../../formats/json/parser.js");
 
-const json_mime    = "application/json";
-const ce_json_mime = "application/cloudevents+json";
+const Constants = require("./constants.js");
 
-const content_type_header = "content-type";
 const ce_structured_content_type = "application/cloudevents";
 
 const structured = "structured";
@@ -12,14 +10,14 @@ const binary = "binary";
 
 const jsonParserSpec02 = new JSONParser(new Spec02());
 const parsers = {};
-parsers[json_mime]    = jsonParserSpec02;
-parsers[ce_json_mime] = jsonParserSpec02;
+parsers[Constants.MIME_JSON]    = jsonParserSpec02;
+parsers[Constants.MIME_CE_JSON] = jsonParserSpec02;
 
 const allowed_binary_content_types = [];
-allowed_binary_content_types.push(json_mime);
+allowed_binary_content_types.push(Constants.MIME_JSON);
 
 const allowed_structured_content_types = [];
-allowed_structured_content_types.push(ce_json_mime);
+allowed_structured_content_types.push(Constants.MIME_CE_JSON);
 
 function validate_args(payload, headers) {
   if(!payload){
@@ -30,7 +28,7 @@ function validate_args(payload, headers) {
     throw {message: "headers is null or undefined"};
   }
 
-  if(!headers[content_type_header]){
+  if(!headers[Constants.HEADER_CONTENT_TYPE]){
     throw {message: "content-type header not found"};
   }
 }
@@ -38,9 +36,10 @@ function validate_args(payload, headers) {
 // Is it binary or structured?
 function resolve_binding_name(payload, headers) {
 
-  var contentType = headers[content_type_header];
+  var contentType = headers[Constants.HEADER_CONTENT_TYPE];
   if(contentType.startsWith(ce_structured_content_type)){
     // Structured
+    console.log(allowed_structured_content_types);
     if(allowed_structured_content_types.includes(contentType)){
       return structured;
     } else {
@@ -65,7 +64,7 @@ Unmarshaller.prototype.unmarshall = function(payload, headers) {
 
   // Resolve the binding
   var bindingName = resolve_binding_name(payload, headers);
-  var contentType = headers[content_type_header];
+  var contentType = headers[Constants.HEADER_CONTENT_TYPE];
 
   if(bindingName === structured){
     var parser = parsers[contentType];