diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 4242213..5b87d41 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -19,5 +19,6 @@
 # If you keep the line number information, uncomment this to
 # hide the original source file name.
 #-renamesourcefileattribute SourceFile
+-dontobfuscate
 -keep,allowoptimization class is.xyz.mpv.** { public protected *; }
 -keep,allowoptimization class com.arthenica.** { public protected *; }
\ No newline at end of file
diff --git a/app/src/main/java/live/mehiz/mpvkt/ui/player/PlayerViewModel.kt b/app/src/main/java/live/mehiz/mpvkt/ui/player/PlayerViewModel.kt
index e4f489f..1ebca41 100644
--- a/app/src/main/java/live/mehiz/mpvkt/ui/player/PlayerViewModel.kt
+++ b/app/src/main/java/live/mehiz/mpvkt/ui/player/PlayerViewModel.kt
@@ -204,6 +204,7 @@ class PlayerViewModel(
   }
 
   fun updateChapter(index: Long) {
+    if (chapters.isEmpty()) return
     _currentChapter.update { chapters[index.toInt()] }
   }