diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt
index e48d9de7c8..b9f267d218 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt
@@ -832,11 +832,11 @@ class ReaderActivity :
         val noDefault = manga.viewer == -1
         val mangaViewer = presenter.getMangaViewer()
         val newViewer = when (mangaViewer) {
-            RIGHT_TO_LEFT -> R2LPagerViewer(this)
+            LEFT_TO_RIGHT -> L2RPagerViewer(this)
             VERTICAL -> VerticalPagerViewer(this)
             WEBTOON -> WebtoonViewer(this)
             VERTICAL_PLUS -> WebtoonViewer(this, hasMargins = true)
-            else -> L2RPagerViewer(this)
+            else -> R2LPagerViewer(this)
         }
 
         if (noDefault && presenter.manga?.viewer!! > 0) {
diff --git a/app/src/main/java/eu/kanade/tachiyomi/widget/MaterialSpinnerView.kt b/app/src/main/java/eu/kanade/tachiyomi/widget/MaterialSpinnerView.kt
index 2730879588..5263c823d0 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/widget/MaterialSpinnerView.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/widget/MaterialSpinnerView.kt
@@ -102,14 +102,18 @@ class MaterialSpinnerView @JvmOverloads constructor(context: Context, attrs: Att
     }
 
     fun setSelection(selection: Int) {
-        popup?.menu?.get(selectedPosition)?.let {
-            it.icon = ContextCompat.getDrawable(context, R.drawable.ic_blank_24dp)
-            it.title = entries[selectedPosition]
+        if (selectedPosition >= 0 && selectedPosition < popup?.menu?.size() ?: 0) {
+            popup?.menu?.get(selectedPosition)?.let {
+                it.icon = ContextCompat.getDrawable(context, R.drawable.ic_blank_24dp)
+                it.title = entries[selectedPosition]
+            }
         }
         selectedPosition = selection
-        popup?.menu?.get(selectedPosition)?.let {
-            it.icon = tintedCheck()
-            it.title = it.title?.tintText(blendedAccent)
+        if (selectedPosition >= 0 && selectedPosition < popup?.menu?.size() ?: 0) {
+            popup?.menu?.get(selectedPosition)?.let {
+                it.icon = tintedCheck()
+                it.title = it.title?.tintText(blendedAccent)
+            }
         }
         binding.detailView.text = entries.getOrNull(selection).orEmpty()
     }