diff --git a/src/all/pixiv/build.gradle b/src/all/pixiv/build.gradle
index dba0fad2d..c458e4795 100644
--- a/src/all/pixiv/build.gradle
+++ b/src/all/pixiv/build.gradle
@@ -6,7 +6,7 @@ ext {
     extName = 'Pixiv'
     pkgNameSuffix = 'all.pixiv'
     extClass = '.PixivFactory'
-    extVersionCode = 7
+    extVersionCode = 8
     isNsfw = true
 }
 
diff --git a/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/Pixiv.kt b/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/Pixiv.kt
index 98a92ba10..4e3ba1667 100644
--- a/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/Pixiv.kt
+++ b/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/Pixiv.kt
@@ -298,7 +298,9 @@ class Pixiv(override val lang: String) : HttpSource() {
         val (id, isSeries) = parseSMangaUrl(manga.url)
 
         if (isSeries) {
-            val series = ApiCall("/touch/ajax/illust/series/$id").executeApi<PixivSeries>()
+            val series = ApiCall("/touch/ajax/illust/series/$id")
+                .executeApi<PixivSeriesDetails>().series!!
+
             val illusts = getSeriesIllustsCached(id)
 
             if (series.id != null && series.userId != null) {
@@ -316,7 +318,8 @@ class Pixiv(override val lang: String) : HttpSource() {
             val tags = illusts.flatMap { it.tags ?: emptyList() }.toSet()
             if (tags.isNotEmpty()) manga.genre = tags.joinToString()
 
-            (series.coverImage ?: illusts.firstOrNull()?.url)?.let { manga.thumbnail_url = it }
+            val coverImage = series.coverImage?.let { if (it.isString) it.content else null }
+            (coverImage ?: illusts.firstOrNull()?.url)?.let { manga.thumbnail_url = it }
         } else {
             val illust = getIllustCached(id)
 
@@ -349,7 +352,7 @@ class Pixiv(override val lang: String) : HttpSource() {
                 setUrlWithoutDomain("/artworks/${illust.id!!}")
                 name = illust.title ?: "(null)"
                 date_upload = (illust.upload_timestamp ?: 0) * 1000
-                chapter_number = i.toFloat()
+                chapter_number = (illusts.size - i).toFloat()
             }
         }
 
diff --git a/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/PixivTypes.kt b/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/PixivTypes.kt
index 9e6bcfcb7..0c57be291 100644
--- a/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/PixivTypes.kt
+++ b/src/all/pixiv/src/eu/kanade/tachiyomi/extension/all/pixiv/PixivTypes.kt
@@ -1,5 +1,6 @@
 package eu.kanade.tachiyomi.extension.all.pixiv
 import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonPrimitive
 
 @Serializable
 internal data class PixivApiResponse<T>(
@@ -59,10 +60,15 @@ internal data class PixivAuthorDetails(
     val user_name: String? = null,
 )
 
+@Serializable
+internal data class PixivSeriesDetails(
+    val series: PixivSeries?,
+)
+
 @Serializable
 internal data class PixivSeries(
     val caption: String? = null,
-    val coverImage: String? = null,
+    val coverImage: JsonPrimitive? = null,
     val id: String? = null,
     val title: String? = null,
     val userId: String? = null,