diff --git a/ghost/admin/app/components/gh-image-uploader.js b/ghost/admin/app/components/gh-image-uploader.js
index 62135fe111..d5ec51113a 100644
--- a/ghost/admin/app/components/gh-image-uploader.js
+++ b/ghost/admin/app/components/gh-image-uploader.js
@@ -30,7 +30,7 @@ export default Component.extend({
     text: '',
     altText: '',
     saveButton: true,
-    accept: null,
+    accept: '',
     extensions: null,
     uploadUrl: null,
     validate: null,
@@ -85,9 +85,8 @@ export default Component.extend({
         return htmlSafe(`width: ${width}`);
     }),
 
-    didReceiveAttrs() {
-        let image = this.get('image');
-        this.set('url', image);
+    init() {
+        this._super(...arguments);
 
         if (!this.get('accept')) {
             this.set('accept', this.get('_defaultAccept'));
@@ -100,6 +99,11 @@ export default Component.extend({
         }
     },
 
+    didReceiveAttrs() {
+        let image = this.get('image');
+        this.set('url', image);
+    },
+
     actions: {
         fileSelected(fileList, resetInput) {
             // can't use array destructuring here as FileList is not a strict