diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/feed/FeedPresenter.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/feed/FeedPresenter.kt
index 993ae1070..fe43cc223 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/feed/FeedPresenter.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/feed/FeedPresenter.kt
@@ -326,6 +326,7 @@ open class FeedPresenter(
      * @param sManga the manga from the source.
      * @return a manga from the database.
      */
+    @Synchronized
     private fun networkToLocalManga(sManga: SManga, sourceId: Long): Manga {
         var localManga = runBlocking { getManga.await(sManga.url, sourceId) }
         if (localManga == null) {
diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/feed/SourceFeedPresenter.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/feed/SourceFeedPresenter.kt
index 6358e0157..8551c7219 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/feed/SourceFeedPresenter.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/feed/SourceFeedPresenter.kt
@@ -282,6 +282,7 @@ open class SourceFeedPresenter(
      * @param sManga the manga from the source.
      * @return a manga from the database.
      */
+    @Synchronized
     private fun networkToLocalManga(sManga: SManga, sourceId: Long): Manga {
         var localManga = runBlocking { getManga.await(sManga.url, sourceId) }
         if (localManga == null) {