diff --git a/static/coffee/screenly-ose.coffee b/static/coffee/screenly-ose.coffee
index 61bee5ea..e70a69d1 100644
--- a/static/coffee/screenly-ose.coffee
+++ b/static/coffee/screenly-ose.coffee
@@ -24,6 +24,8 @@ get_mimetype = (filename) =>
 
 # Models
 
+default_duration = 10
+
 # Tell Backbone to send its saves as JSON-encoded.
 Backbone.emulateJSON = on
 
@@ -36,7 +38,7 @@ API.Asset = class Asset extends Backbone.Model
     uri: ''
     start_date: now()
     end_date: now()
-    duration: 10
+    duration: default_duration
 
 API.Assets = class Assets extends Backbone.Collection
   url: "/api/assets"
@@ -118,6 +120,7 @@ class EditAssetView extends Backbone.View
 
     (@$ 'input, select').prop 'disabled', on
     save.done (data) =>
+      default_duration = @model.get 'duration'
       @collection.add @model if not @model.collection
       (@$el.children ":first").modal 'hide'
       _.extend @model.attributes, data
@@ -164,6 +167,7 @@ class EditAssetView extends Backbone.View
   updateMimetype: (filename) =>
     mt = get_mimetype filename
     @$fv 'mimetype', mt if mt
+    _.defer @change
 
 
 class AssetRowView extends Backbone.View
diff --git a/static/js/screenly-ose.js b/static/js/screenly-ose.js
index e8a871c8..73d20c7b 100644
--- a/static/js/screenly-ose.js
+++ b/static/js/screenly-ose.js
@@ -5,7 +5,7 @@
 
 
 (function() {
-  var API, App, Asset, AssetRowView, Assets, AssetsView, EditAssetView, date_to, delay, get_mimetype, get_template, mimetypes, now, y2ts, years_from_now,
+  var API, App, Asset, AssetRowView, Assets, AssetsView, EditAssetView, date_to, default_duration, delay, get_mimetype, get_template, mimetypes, now, y2ts, years_from_now,
     _this = this,
     __indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; },
@@ -68,6 +68,8 @@
     }
   };
 
+  default_duration = 10;
+
   Backbone.emulateJSON = true;
 
   API.Asset = Asset = (function(_super) {
@@ -90,7 +92,7 @@
         uri: '',
         start_date: now(),
         end_date: now(),
-        duration: 10
+        duration: default_duration
       };
     };
 
@@ -268,6 +270,7 @@
       }
       (this.$('input, select')).prop('disabled', true);
       save.done(function(data) {
+        default_duration = _this.model.get('duration');
         if (!_this.model.collection) {
           _this.collection.add(_this.model);
         }
@@ -343,8 +346,9 @@
       var mt;
       mt = get_mimetype(filename);
       if (mt) {
-        return this.$fv('mimetype', mt);
+        this.$fv('mimetype', mt);
       }
+      return _.defer(this.change);
     };
 
     return EditAssetView;