diff --git a/ghost/admin/app/controllers/posts.js b/ghost/admin/app/controllers/posts.js
index 9952aebbb2..bc5811e2e1 100644
--- a/ghost/admin/app/controllers/posts.js
+++ b/ghost/admin/app/controllers/posts.js
@@ -8,101 +8,6 @@ const {
 } = Ember;
 const {equal} = computed;
 
-// a custom sort function is needed in order to sort the posts list the same way the server would:
-//     status: scheduled, draft, published
-//     publishedAtUTC: DESC
-//     updatedAtUTC: DESC
-//     id: DESC
-function comparator(item1, item2) {
-    let updated1 = item1.get('updatedAtUTC');
-    let updated2 = item2.get('updatedAtUTC');
-    let idResult,
-        publishedAtResult,
-        statusResult,
-        updatedAtResult;
-
-    // when `updatedAt` is undefined, the model is still
-    // being written to with the results from the server
-    if (item1.get('isNew') || !updated1) {
-        return -1;
-    }
-
-    if (item2.get('isNew') || !updated2) {
-        return 1;
-    }
-
-    idResult = compare(parseInt(item1.get('id')), parseInt(item2.get('id')));
-    statusResult = statusCompare(item1, item2);
-    updatedAtResult = compare(updated1.valueOf(), updated2.valueOf());
-    publishedAtResult = publishedAtCompare(item1, item2);
-
-    if (statusResult === 0) {
-        if (publishedAtResult === 0) {
-            if (updatedAtResult === 0) {
-                // This should be DESC
-                return idResult * -1;
-            }
-            // This should be DESC
-            return updatedAtResult * -1;
-        }
-        // This should be DESC
-        return publishedAtResult * -1;
-    }
-
-    return statusResult;
-}
-
-function statusCompare(item1, item2) {
-    let status1 = item1.get('status');
-    let status2 = item2.get('status');
-
-    // if any of those is empty
-    if (!status1 && !status2) {
-        return 0;
-    }
-
-    if (!status1 && status2) {
-        return -1;
-    }
-
-    if (!status2 && status1) {
-        return 1;
-    }
-
-    // We have to make sure, that scheduled posts will be listed first
-    // after that, draft and published will be sorted alphabetically and don't need
-    // any manual comparison.
-
-    if (status1 === 'scheduled' && (status2 === 'draft' || status2 === 'published')) {
-        return -1;
-    }
-
-    if (status2 === 'scheduled' && (status1 === 'draft' || status1 === 'published')) {
-        return 1;
-    }
-
-    return compare(status1.valueOf(), status2.valueOf());
-}
-
-function publishedAtCompare(item1, item2) {
-    let published1 = item1.get('publishedAtUTC');
-    let published2 = item2.get('publishedAtUTC');
-
-    if (!published1 && !published2) {
-        return 0;
-    }
-
-    if (!published1 && published2) {
-        return -1;
-    }
-
-    if (!published2 && published1) {
-        return 1;
-    }
-
-    return compare(published1.valueOf(), published2.valueOf());
-}
-
 export default Controller.extend({
     feature: service(),
 
@@ -112,10 +17,8 @@ export default Controller.extend({
     postListFocused: equal('keyboardFocus', 'postList'),
     postContentFocused: equal('keyboardFocus', 'postContent'),
 
-    sortedPosts: computed('model.@each.status', 'model.@each.publishedAtUTC', 'model.@each.isNew', 'model.@each.updatedAtUTC', function () {
-        let postsArray = this.get('model').toArray();
-
-        return postsArray.sort(comparator);
+    sortedPosts: computed('model.@each.{status,publishedAtUTC,isNew,updatedAtUTC}', function () {
+        return this.get('model').toArray().sort(compare);
     }),
 
     actions: {
diff --git a/ghost/admin/app/models/post.js b/ghost/admin/app/models/post.js
index 804cdafec5..629b689403 100644
--- a/ghost/admin/app/models/post.js
+++ b/ghost/admin/app/models/post.js
@@ -6,12 +6,65 @@ import { belongsTo, hasMany } from 'ember-data/relationships';
 import ValidationEngine from 'ghost-admin/mixins/validation-engine';
 
 const {
+    Comparable,
+    compare,
     computed,
     inject: {service}
 } = Ember;
 const {equal, filterBy} = computed;
 
-export default Model.extend(ValidationEngine, {
+function statusCompare(postA, postB) {
+    let status1 = postA.get('status');
+    let status2 = postB.get('status');
+
+    // if any of those is empty
+    if (!status1 && !status2) {
+        return 0;
+    }
+
+    if (!status1 && status2) {
+        return -1;
+    }
+
+    if (!status2 && status1) {
+        return 1;
+    }
+
+    // We have to make sure, that scheduled posts will be listed first
+    // after that, draft and published will be sorted alphabetically and don't need
+    // any manual comparison.
+
+    if (status1 === 'scheduled' && (status2 === 'draft' || status2 === 'published')) {
+        return -1;
+    }
+
+    if (status2 === 'scheduled' && (status1 === 'draft' || status1 === 'published')) {
+        return 1;
+    }
+
+    return compare(status1.valueOf(), status2.valueOf());
+}
+
+function publishedAtCompare(postA, postB) {
+    let published1 = postA.get('publishedAtUTC');
+    let published2 = postB.get('publishedAtUTC');
+
+    if (!published1 && !published2) {
+        return 0;
+    }
+
+    if (!published1 && published2) {
+        return -1;
+    }
+
+    if (!published2 && published1) {
+        return 1;
+    }
+
+    return compare(published1.valueOf(), published2.valueOf());
+}
+
+export default Model.extend(Comparable, ValidationEngine, {
     validationType: 'post',
 
     uuid: attr('string'),
@@ -95,5 +148,49 @@ export default Model.extend(ValidationEngine, {
 
     isAuthoredByUser(user) {
         return parseInt(user.get('id'), 10) === parseInt(this.get('authorId'), 10);
+    },
+
+    // a custom sort function is needed in order to sort the posts list the same way the server would:
+    //     status: scheduled, draft, published
+    //     publishedAt: DESC
+    //     updatedAt: DESC
+    //     id: DESC
+    compare(postA, postB) {
+        let updated1 = postA.get('updatedAtUTC');
+        let updated2 = postB.get('updatedAtUTC');
+        let idResult,
+            publishedAtResult,
+            statusResult,
+            updatedAtResult;
+
+        // when `updatedAt` is undefined, the model is still
+        // being written to with the results from the server
+        if (postA.get('isNew') || !updated1) {
+            return -1;
+        }
+
+        if (postB.get('isNew') || !updated2) {
+            return 1;
+        }
+
+        idResult = compare(parseInt(postA.get('id')), parseInt(postB.get('id')));
+        statusResult = statusCompare(postA, postB);
+        updatedAtResult = compare(updated1.valueOf(), updated2.valueOf());
+        publishedAtResult = publishedAtCompare(postA, postB);
+
+        if (statusResult === 0) {
+            if (publishedAtResult === 0) {
+                if (updatedAtResult === 0) {
+                    // This should be DESC
+                    return idResult * -1;
+                }
+                // This should be DESC
+                return updatedAtResult * -1;
+            }
+            // This should be DESC
+            return publishedAtResult * -1;
+        }
+
+        return statusResult;
     }
 });