diff --git a/Mastodon/Extension/CoreDataStack/MastodonUser.swift b/Mastodon/Extension/CoreDataStack/MastodonUser.swift
index bb99b15d4..7035a987b 100644
--- a/Mastodon/Extension/CoreDataStack/MastodonUser.swift
+++ b/Mastodon/Extension/CoreDataStack/MastodonUser.swift
@@ -58,10 +58,18 @@ extension MastodonUser {
         return URL(string: header)
     }
     
+    public func headerImageURLWithFallback(domain: String) -> URL {
+        return URL(string: header) ?? URL(string: "https://\(domain)/headers/original/missing.png")!
+    }
+    
     public func avatarImageURL() -> URL? {
         return URL(string: avatar)
     }
     
+    public func avatarImageURLWithFallback(domain: String) -> URL {
+        return URL(string: avatar) ?? URL(string: "https://\(domain)/avatars/original/missing.png")!
+    }
+    
 }
 
 extension MastodonUser {
diff --git a/Mastodon/Scene/MediaPreview/MediaPreviewViewModel.swift b/Mastodon/Scene/MediaPreview/MediaPreviewViewModel.swift
index 1b0cc6def..f3037c080 100644
--- a/Mastodon/Scene/MediaPreview/MediaPreviewViewModel.swift
+++ b/Mastodon/Scene/MediaPreview/MediaPreviewViewModel.swift
@@ -59,7 +59,7 @@ final class MediaPreviewViewModel: NSObject {
         let managedObjectContext = self.context.managedObjectContext
         managedObjectContext.performAndWait {
             let account = managedObjectContext.object(with: meta.accountObjectID) as! MastodonUser
-            let avatarURL = account.headerImageURL() ?? URL(string: "https://example.com")!     // assert URL exist
+            let avatarURL = account.headerImageURLWithFallback(domain: account.domain)
             let meta = MediaPreviewImageViewModel.RemoteImagePreviewMeta(url: avatarURL, thumbnail: meta.preloadThumbnailImage)
             let mediaPreviewImageModel = MediaPreviewImageViewModel(meta: meta)
             let mediaPreviewImageViewController = MediaPreviewImageViewController()
@@ -79,7 +79,7 @@ final class MediaPreviewViewModel: NSObject {
         let managedObjectContext = self.context.managedObjectContext
         managedObjectContext.performAndWait {
             let account = managedObjectContext.object(with: meta.accountObjectID) as! MastodonUser
-            let avatarURL = account.avatarImageURL() ?? URL(string: "https://example.com")!     // assert URL exist
+            let avatarURL = account.avatarImageURLWithFallback(domain: account.domain)
             let meta = MediaPreviewImageViewModel.RemoteImagePreviewMeta(url: avatarURL, thumbnail: meta.preloadThumbnailImage)
             let mediaPreviewImageModel = MediaPreviewImageViewModel(meta: meta)
             let mediaPreviewImageViewController = MediaPreviewImageViewController()