diff --git a/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt b/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
index 20d0887b8..f6325732e 100644
--- a/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
+++ b/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
@@ -50,7 +50,7 @@ abstract class BaseReadAloudService : BaseService(),
     var readAloudNumber: Int = 0
     var textChapter: TextChapter? = null
     var pageIndex = 0
-    private val dsRunnable: Runnable? = Runnable { doDs() }
+    private val dsRunnable: Runnable = Runnable { doDs() }
 
     override fun onCreate() {
         super.onCreate()