diff --git a/index.js b/index.js
index cfa502d4..f7bc2453 100644
--- a/index.js
+++ b/index.js
@@ -416,7 +416,7 @@ function cms(loopbackApplication, options) {
 
       aws.getS3Credentials(req.query["path"], req.query["fileType"], function(error, credentials) {
         if (error) {
-          res.status(500).send(error);
+          res.status(error.status).send(error.message);
         }
         res.send(credentials);
       });
diff --git a/server/aws.js b/server/aws.js
index 1600a5ce..a296ad77 100644
--- a/server/aws.js
+++ b/server/aws.js
@@ -22,6 +22,7 @@
  THE SOFTWARE.
  */
 
+var _ = require('lodash');
 var uuid = require('node-uuid');
 var moment = require("moment");
 var crypto = require("crypto");
@@ -38,16 +39,26 @@ var awsConfig;
 function getS3Credentials(path, fileType, callback) {
   var acceptableFileTypes = awsConfig.s3.path[path];
   if (!acceptableFileTypes) {
-    callback({error: "Invalid path value"});
+    var error = new Error('Invalid path value');
+    var error.status = 400;
+    callback(error);
     return;
   }
   if (fileType == undefined || fileType == null) {
-    callback({error: "Please provide a fileType"});
+    var error = new Error('Please provide a fileType');
+    var error.status = 400;
+    callback(error);
     return;
   }
   var fileExtension = acceptableFileTypes[fileType];
   if (!fileExtension) {
-    callback({error: "Invalid fileType for path"});
+    var files = [];
+    _.forEach(acceptableFileTypes, function(type) {
+      files.push(type);
+    });
+    var error = new Error('The file being uploaded is not an accepted file type for this form. Allowed file types are (' + files.join(', ') + ').');
+    error.status = 400;
+    callback(error);
     return;
   } 
   var expirationLength = 900; //15min