diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/migration/manga/process/MigrationProcessAdapter.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/migration/manga/process/MigrationProcessAdapter.kt
index ed3d9a8224..8fe5d2c24b 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/migration/manga/process/MigrationProcessAdapter.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/migration/manga/process/MigrationProcessAdapter.kt
@@ -111,7 +111,7 @@ class MigrationProcessAdapter(
         if (MigrationFlags.hasChapters(flags)) {
             val prevMangaChapters = db.getChapters(prevManga).executeAsBlocking()
             val maxChapterRead =
-                prevMangaChapters.filter { it.read }.maxOf { it.chapter_number }
+                prevMangaChapters.filter { it.read }.maxOfOrNull { it.chapter_number } ?: 0f
             val dbChapters = db.getChapters(manga).executeAsBlocking()
             val prevHistoryList = db.getHistoryByMangaId(prevManga.id!!).executeAsBlocking()
             val historyList = mutableListOf<History>()
diff --git a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
index b1567d8015..d4266c42e2 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
@@ -96,7 +96,7 @@ fun syncChaptersWithSource(
 
     // Return if there's nothing to add, delete or change, avoid unnecessary db transactions.
     if (toAdd.isEmpty() && toDelete.isEmpty() && toChange.isEmpty()) {
-        val newestDate = dbChapters.maxOf { it.date_upload }
+        val newestDate = dbChapters.maxOfOrNull { it.date_upload } ?: 0L
         if (newestDate != 0L && newestDate != manga.last_update) {
             manga.last_update = newestDate
             db.updateLastUpdated(manga).executeAsBlocking()
@@ -149,7 +149,7 @@ fun syncChaptersWithSource(
         db.fixChaptersSourceOrder(sourceChapters).executeAsBlocking()
 
         // Set this manga as updated since chapters were changed
-        val newestChapterDate = db.getChapters(manga).executeAsBlocking().maxOf { it.date_upload }
+        val newestChapterDate = db.getChapters(manga).executeAsBlocking().maxOfOrNull { it.date_upload } ?: 0L
         if (newestChapterDate == 0L) {
             if (toAdd.isNotEmpty()) {
                 manga.last_update = Date().time