diff --git a/komga/src/main/kotlin/org/gotson/komga/infrastructure/mediacontainer/epub/EpubExtractor.kt b/komga/src/main/kotlin/org/gotson/komga/infrastructure/mediacontainer/epub/EpubExtractor.kt
index ff1a312ad..51098fa12 100644
--- a/komga/src/main/kotlin/org/gotson/komga/infrastructure/mediacontainer/epub/EpubExtractor.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/infrastructure/mediacontainer/epub/EpubExtractor.kt
@@ -324,7 +324,7 @@ class EpubExtractor(
       file.fileName to
         doc?.select("span.koboSpan")?.mapNotNull { koboSpan ->
           val id = koboSpan.id()
-          if (!id.isNullOrBlank()) {
+          if (id.isNotBlank()) {
             // progression is built from the position in the file of each koboSpan, divided by the file size
             val progression = koboSpan.sourceRange().endPos().toFloat() / file.fileSize!!.toFloat()
             Pair(id, progression)