diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 3e255274..733d756a 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,5 +1,14 @@
 Changelog of MifareClassicTool (MCT):
 
+Version 4.2.1:
+ * Added Russian translation (Thanks to "IIIef").
+ * Added Portuguese translation (Thanks to "YaBa").
+ * Fixed crash on Samsung Galaxy S24 Ultra
+   (Thanks to Eduardo Speroni).
+ * Fixed some crashes related to Android 14.
+ * Added more well known keys to the extended key file.
+   (extended-std.keys file will be updated automatically.)
+
 Version 4.2.0:
  * Choosing the language is now possible.
  * Choosing the theme (light/dark) is now possible
diff --git a/Mifare Classic Tool/app/build.gradle b/Mifare Classic Tool/app/build.gradle
index 9b039cbc..28fe00b1 100755
--- a/Mifare Classic Tool/app/build.gradle	
+++ b/Mifare Classic Tool/app/build.gradle	
@@ -11,8 +11,8 @@ android {
         applicationId "de.syss.MifareClassicTool"
         minSdk 19
         targetSdk 33
-        versionCode 65
-        versionName '4.2.0'
+        versionCode 66
+        versionName '4.2.1'
     }
 
     androidResources {
diff --git a/metadata/en-US/changelogs/66.txt b/metadata/en-US/changelogs/66.txt
new file mode 100644
index 00000000..422f1f00
--- /dev/null
+++ b/metadata/en-US/changelogs/66.txt
@@ -0,0 +1,8 @@
+ * Added Russian translation (Thanks to "IIIef").
+ * Added Portuguese translation (Thanks to "YaBa").
+ * Fixed crash on Samsung Galaxy S24 Ultra
+   (Thanks to Eduardo Speroni).
+ * Fixed some crashes related to Android 14.
+ * Added more well known keys to the extended key file.
+   (extended-std.keys file will be updated automatically.)
+