diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/backup/models/BackupManga.kt b/app/src/main/java/eu/kanade/tachiyomi/data/backup/models/BackupManga.kt
index d642cdee4..e32fc151f 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/backup/models/BackupManga.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/backup/models/BackupManga.kt
@@ -42,7 +42,7 @@ data class BackupManga(
     @ProtoNumber(104) var history: List<BackupHistory> = emptyList(),
     @ProtoNumber(105) var updateStrategy: UpdateStrategy = UpdateStrategy.ALWAYS_UPDATE,
     @ProtoNumber(106) var lastModifiedAt: Long = 0,
-    @ProtoNumber(107) var favoriteModifiedAt: Long? = 0,
+    @ProtoNumber(107) var favoriteModifiedAt: Long? = null,
 
     // SY specific values
     @ProtoNumber(600) var mergedMangaReferences: List<BackupMergedMangaReference> = emptyList(),
diff --git a/data/src/main/sqldelight/tachiyomi/migrations/28.sqm b/data/src/main/sqldelight/tachiyomi/migrations/28.sqm
index b4d98546a..0cd1c4c07 100644
--- a/data/src/main/sqldelight/tachiyomi/migrations/28.sqm
+++ b/data/src/main/sqldelight/tachiyomi/migrations/28.sqm
@@ -1,7 +1,7 @@
-ALTER TABLE mangas ADD COLUMN last_modified_at INTEGER AS Long NOT NULL;
+ALTER TABLE mangas ADD COLUMN last_modified_at INTEGER AS Long NOT NULL DEFAULT 0;
 ALTER TABLE mangas ADD COLUMN favorite_modified_at INTEGER AS Long;
-ALTER TABLE mangas_categories ADD COLUMN last_modified_at INTEGER AS Long NOT NULL;
-ALTER TABLE chapters ADD COLUMN last_modified_at INTEGER AS Long NOT NULL;
+ALTER TABLE mangas_categories ADD COLUMN last_modified_at INTEGER AS Long NOT NULL DEFAULT 0;
+ALTER TABLE chapters ADD COLUMN last_modified_at INTEGER AS Long NOT NULL DEFAULT 0;
 
 UPDATE mangas SET last_modified_at = strftime('%s', 'now');
 UPDATE mangas SET favorite_modified_at = strftime('%s', 'now') WHERE favorite = 1;
diff --git a/domain/src/main/java/tachiyomi/domain/manga/model/Manga.kt b/domain/src/main/java/tachiyomi/domain/manga/model/Manga.kt
index a4d3699f5..5863273c3 100644
--- a/domain/src/main/java/tachiyomi/domain/manga/model/Manga.kt
+++ b/domain/src/main/java/tachiyomi/domain/manga/model/Manga.kt
@@ -149,7 +149,7 @@ data class Manga(
             updateStrategy = UpdateStrategy.ALWAYS_UPDATE,
             initialized = false,
             lastModifiedAt = 0L,
-            favoriteModifiedAt = 0L,
+            favoriteModifiedAt = null,
             // SY -->
             filteredScanlators = null,
             // SY <--