diff --git a/app/src/main/java/io/legado/app/utils/EncoderUtils.kt b/app/src/main/java/io/legado/app/utils/EncoderUtils.kt
index 504d4a9c1..0b3300897 100644
--- a/app/src/main/java/io/legado/app/utils/EncoderUtils.kt
+++ b/app/src/main/java/io/legado/app/utils/EncoderUtils.kt
@@ -125,6 +125,8 @@ object EncoderUtils {
      * @param key            The key.
      * @param algorithm      The name of algorithm.
      * @param transformation The name of the transformation, e.g., <i>DES/CBC/PKCS5Padding</i>.
+     * @param iv             The buffer with the IV. The contents of the
+     * buffer are copied to protect against subsequent modification.
      * @param isEncrypt      True to encrypt, false otherwise.
      * @return the bytes of symmetric encryption or decryption
      */
diff --git a/build.gradle b/build.gradle
index 844e4e6b6..967f30950 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.5.30-M1'
+    ext.kotlin_version = '1.5.30'
     repositories {
         google()
         mavenCentral()