diff --git a/komga/src/main/kotlin/org/gotson/komga/domain/model/SeriesMetadataPatch.kt b/komga/src/main/kotlin/org/gotson/komga/domain/model/SeriesMetadataPatch.kt
index 67389800b..328a89893 100644
--- a/komga/src/main/kotlin/org/gotson/komga/domain/model/SeriesMetadataPatch.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/domain/model/SeriesMetadataPatch.kt
@@ -9,7 +9,7 @@ data class SeriesMetadataPatch(
   val publisher: String?,
   val ageRating: Int?,
   val language: String?,
-  val genres: Set<String>,
+  val genres: Set<String>?,
 
   val collections: List<String>
 )
diff --git a/komga/src/main/kotlin/org/gotson/komga/domain/service/MetadataLifecycle.kt b/komga/src/main/kotlin/org/gotson/komga/domain/service/MetadataLifecycle.kt
index 7befdf0f1..214203678 100644
--- a/komga/src/main/kotlin/org/gotson/komga/domain/service/MetadataLifecycle.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/domain/service/MetadataLifecycle.kt
@@ -134,7 +134,7 @@ class MetadataLifecycle(
               title = patches.mostFrequent { it.title },
               titleSort = patches.mostFrequent { it.titleSort },
               status = patches.mostFrequent { it.status },
-              genres = patches.flatMap { it.genres }.toSet(),
+              genres = patches.mapNotNull { it.genres }.flatten().toSet(),
               language = patches.mostFrequent { it.language },
               summary = null,
               readingDirection = patches.mostFrequent { it.readingDirection },
diff --git a/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/comicinfo/ComicInfoProvider.kt b/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/comicinfo/ComicInfoProvider.kt
index 96f30768d..e09f97025 100644
--- a/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/comicinfo/ComicInfoProvider.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/comicinfo/ComicInfoProvider.kt
@@ -73,7 +73,7 @@ class ComicInfoProvider(
         else -> null
       }
 
-      val genres = comicInfo.genre?.split(',')?.map { it.trim() }?.toSet() ?: emptySet()
+      val genres = comicInfo.genre?.split(',')?.map { it.trim() }?.toSet()
 
       return SeriesMetadataPatch(
         title = comicInfo.series,
diff --git a/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/epub/EpubMetadataProvider.kt b/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/epub/EpubMetadataProvider.kt
index ff4b1d002..79f399d03 100644
--- a/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/epub/EpubMetadataProvider.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/infrastructure/metadata/epub/EpubMetadataProvider.kt
@@ -88,8 +88,8 @@ class EpubMetadataProvider(
         publisher = publisher,
         ageRating = null,
         summary = null,
-        language = if(language != null && BCP47TagValidator.isValid(language)) language else null,
-        genres = if(genre != null) setOf(genre) else emptySet(),
+        language = if (language != null && BCP47TagValidator.isValid(language)) language else null,
+        genres = genre?.let { setOf(genre) },
         collections = emptyList()
       )
     }