diff --git a/serial/build.gradle b/serial/build.gradle
index 9d03e43..a1a10ce 100644
--- a/serial/build.gradle
+++ b/serial/build.gradle
@@ -8,8 +8,8 @@ android {
     defaultConfig {
         minSdkVersion 15
         targetSdkVersion 28
-        versionCode 5
-        versionName "1.2"
+        versionCode 6
+        versionName "1.2.1"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         consumerProguardFiles 'consumer-rules.pro'
diff --git a/serial/src/main/java/org/sheedon/serial/Request.java b/serial/src/main/java/org/sheedon/serial/Request.java
index 38e8adc..ff07f3a 100644
--- a/serial/src/main/java/org/sheedon/serial/Request.java
+++ b/serial/src/main/java/org/sheedon/serial/Request.java
@@ -47,7 +47,7 @@ public long backNameCode() {
     private long calcBackNameCode(byte[] nameBytes) {
         long code = 0;
         for (byte nameByte : nameBytes) {
-            code = code * 256 + nameByte & 0xFF;
+            code = code * 256 + (nameByte & 0xFF);
         }
         return code;
     }