diff --git a/ReadMe.txt b/ReadMe.txt
index a75ac76..0ae589e 100644
--- a/ReadMe.txt
+++ b/ReadMe.txt
@@ -61,6 +61,7 @@ CHANGES
 Version 2.8 (2024-xx-xx)
 
 - Updated source code with Emu48 version 1.66+.
+- Fix an USB serial issue with Android 13+ (fix #23).
 
 
 Version 2.7 (2024-06-14)
diff --git a/app/src/main/assets/ReadMe.txt b/app/src/main/assets/ReadMe.txt
index 71490fd..73256e9 100644
--- a/app/src/main/assets/ReadMe.txt
+++ b/app/src/main/assets/ReadMe.txt
@@ -58,6 +58,12 @@ LINKS
 
 CHANGES
 
+Version 2.8 (2024-xx-xx)
+
+- Updated source code with Emu48 version 1.66+.
+- Fix an USB serial issue with Android 13+ (fix #23).
+
+
 Version 2.7 (2024-06-14)
 
 - Updated source code with Emu48 version 1.65+. This new version improve the serial communication.
diff --git a/app/src/main/cpp/emu-jni.c b/app/src/main/cpp/emu-jni.c
index 4089002..cfad6b5 100644
--- a/app/src/main/cpp/emu-jni.c
+++ b/app/src/main/cpp/emu-jni.c
@@ -88,16 +88,14 @@ enum CALLBACK_TYPE {
 };
 
 // https://stackoverflow.com/questions/9630134/jni-how-to-callback-from-c-or-c-to-java
-int mainViewCallback(int type, int param1, int param2, const TCHAR * param3, const TCHAR * param4) {
+int mainViewCallback(int type, int param1, int param2/*, const TCHAR * param3, const TCHAR * param4*/) {
     if (mainActivity) {
         JNIEnv *jniEnv = getJNIEnvironment();
         if(jniEnv) {
             jclass mainActivityClass = (*jniEnv)->GetObjectClass(jniEnv, mainActivity);
             if(mainActivityClass) {
-                jmethodID midStr = (*jniEnv)->GetMethodID(jniEnv, mainActivityClass, "updateCallback", "(IIILjava/lang/String;Ljava/lang/String;)I");
-                jstring utfParam3 = (*jniEnv)->NewStringUTF(jniEnv, param3);
-                jstring utfParam4 = (*jniEnv)->NewStringUTF(jniEnv, param4);
-                int result = (*jniEnv)->CallIntMethod(jniEnv, mainActivity, midStr, type, param1, param2, utfParam3, utfParam4);
+	            jmethodID midStr = (*jniEnv)->GetMethodID(jniEnv, mainActivityClass, "updateCallback", "(III)I");
+	            int result = (*jniEnv)->CallIntMethod(jniEnv, mainActivity, midStr, type, param1, param2);
                 (*jniEnv)->DeleteLocalRef(jniEnv, mainActivityClass);
                 //if(needDetach) ret = (*java_machine)->DetachCurrentThread(java_machine);
                 return result;
@@ -113,18 +111,16 @@ void mainViewUpdateCallback() {
 //		int param2 = ((mainViewRectangleToUpdate.right & 0xFFFF) << 16) | (mainViewRectangleToUpdate.bottom & 0xFFFF);
 //		mainViewCallback(CALLBACK_TYPE_INVALIDATE,
 //		                 param1,
-//		                 param2,
-//		                 NULL, NULL);
+//		                 param2);
 //		SetRectEmpty(&mainViewRectangleToUpdate);
 //	} else
 		mainViewCallback(CALLBACK_TYPE_INVALIDATE,
 		                 0,
-		                 0,
-		                 NULL, NULL);
+		                 0);
 }
 
 void mainViewResizeCallback(int x, int y) {
-    mainViewCallback(CALLBACK_TYPE_WINDOW_RESIZE, x, y, NULL, NULL);
+    mainViewCallback(CALLBACK_TYPE_WINDOW_RESIZE, x, y);
 
     JNIEnv * jniEnv;
     int ret = (*java_machine)->GetEnv(java_machine, (void **) &jniEnv, JNI_VERSION_1_6);
diff --git a/app/src/main/java/org/emulator/calculator/MainScreenView.java b/app/src/main/java/org/emulator/calculator/MainScreenView.java
index 0e2804e..6802b8e 100644
--- a/app/src/main/java/org/emulator/calculator/MainScreenView.java
+++ b/app/src/main/java/org/emulator/calculator/MainScreenView.java
@@ -483,7 +483,7 @@ public class MainScreenView extends PanAndScaleView {
 		canvas.drawLines(pointsBuffer, paintLCD);
 	}
 
-	public void updateCallback(int type, int param1, int param2, String param3, String param4) {
+	public void updateCallback(int type, int param1, int param2) {
 		try {
 			switch (type) {
 				case NativeLib.CALLBACK_TYPE_INVALIDATE:
diff --git a/app/src/main/java/org/emulator/forty/eight/MainActivity.java b/app/src/main/java/org/emulator/forty/eight/MainActivity.java
index d190de5..ca96ba6 100644
--- a/app/src/main/java/org/emulator/forty/eight/MainActivity.java
+++ b/app/src/main/java/org/emulator/forty/eight/MainActivity.java
@@ -1783,12 +1783,11 @@ public class MainActivity extends AppCompatActivity implements NavigationView.On
     // Method used from JNI!
 
 	@SuppressWarnings("UnusedDeclaration")
-    public int updateCallback(int type, int param1, int param2, String param3, String param4) {
-
-        mainScreenView.updateCallback(type, param1, param2, param3, param4);
-        return -1;
-    }
+	public int updateCallback(int type, int param1, int param2) {
 
+		mainScreenView.updateCallback(type, param1, param2);
+		return -1;
+	}
 
     final int GENERIC_READ   = 1;
     final int GENERIC_WRITE  = 2;