diff --git a/app/src/main/java/com/github/libretube/util/FormatShort.kt b/app/src/main/java/com/github/libretube/extensions/FormatShort.kt
similarity index 100%
rename from app/src/main/java/com/github/libretube/util/FormatShort.kt
rename to app/src/main/java/com/github/libretube/extensions/FormatShort.kt
diff --git a/app/src/main/java/com/github/libretube/util/HideKeyboard.kt b/app/src/main/java/com/github/libretube/extensions/HideKeyboard.kt
similarity index 100%
rename from app/src/main/java/com/github/libretube/util/HideKeyboard.kt
rename to app/src/main/java/com/github/libretube/extensions/HideKeyboard.kt
diff --git a/app/src/main/java/com/github/libretube/util/SetWatchProgressLength.kt b/app/src/main/java/com/github/libretube/extensions/SetWatchProgressLength.kt
similarity index 100%
rename from app/src/main/java/com/github/libretube/util/SetWatchProgressLength.kt
rename to app/src/main/java/com/github/libretube/extensions/SetWatchProgressLength.kt
diff --git a/app/src/main/java/com/github/libretube/util/ToID.kt b/app/src/main/java/com/github/libretube/extensions/ToID.kt
similarity index 100%
rename from app/src/main/java/com/github/libretube/util/ToID.kt
rename to app/src/main/java/com/github/libretube/extensions/ToID.kt
diff --git a/app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt b/app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt
index b49abf04a..b6bc85fe2 100644
--- a/app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt
+++ b/app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt
@@ -810,7 +810,7 @@ class PlayerFragment : Fragment() {
                         playlist = RetrofitInstance.api.getPlaylist(playlistId!!)
                         // save the playlist urls in the array
                         playlist.relatedStreams?.forEach { video ->
-                            playlistStreamIds += video.url?.toID()
+                            playlistStreamIds += video.url.toID()
                         }
                         // save playlistNextPage for usage if video is not contained
                         playlistNextPage = playlist.nextpage
diff --git a/app/src/main/java/com/github/libretube/preferences/PreferenceHelper.kt b/app/src/main/java/com/github/libretube/preferences/PreferenceHelper.kt
index d5e4c508c..346ff1204 100644
--- a/app/src/main/java/com/github/libretube/preferences/PreferenceHelper.kt
+++ b/app/src/main/java/com/github/libretube/preferences/PreferenceHelper.kt
@@ -16,7 +16,7 @@ object PreferenceHelper {
     private lateinit var prefContext: Context
     private lateinit var settings: SharedPreferences
     private lateinit var editor: SharedPreferences.Editor
-    val mapper = ObjectMapper()
+    private val mapper = ObjectMapper()
 
     /**
      * set the context that is being used to access the shared preferences
@@ -136,7 +136,6 @@ object PreferenceHelper {
             streams.duration
         )
 
-        val mapper = ObjectMapper()
         val watchHistory = getWatchHistory()
 
         watchHistory += watchHistoryItem
@@ -146,7 +145,6 @@ object PreferenceHelper {
     }
 
     fun removeFromWatchHistory(videoId: String) {
-        val mapper = ObjectMapper()
         val watchHistory = getWatchHistory()
 
         var indexToRemove: Int? = null
@@ -220,7 +218,7 @@ object PreferenceHelper {
     }
 
     fun setLatestVideoId(videoId: String) {
-        setString(PreferenceKeys.LAST_STREAM_VIDEO_ID, videoId)
+        editor.putString(PreferenceKeys.LAST_STREAM_VIDEO_ID, videoId)
     }
 
     fun getLatestVideoId(): String {