diff --git a/app/src/main/java/io/legado/app/constant/AppConst.kt b/app/src/main/java/io/legado/app/constant/AppConst.kt
index 991da0859..d3548c9f1 100644
--- a/app/src/main/java/io/legado/app/constant/AppConst.kt
+++ b/app/src/main/java/io/legado/app/constant/AppConst.kt
@@ -19,6 +19,8 @@ object AppConst {
     const val channelIdReadAloud = "channel_read_aloud"
     const val channelIdWeb = "channel_web"
 
+    const val UA_NAME = "User-Agent"
+
     val userAgent: String by lazy {
         "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36"
     }
diff --git a/app/src/main/java/io/legado/app/data/entities/BookSource.kt b/app/src/main/java/io/legado/app/data/entities/BookSource.kt
index 3236d5796..c09a467dc 100644
--- a/app/src/main/java/io/legado/app/data/entities/BookSource.kt
+++ b/app/src/main/java/io/legado/app/data/entities/BookSource.kt
@@ -69,7 +69,7 @@ data class BookSource(
     @Throws(Exception::class)
     fun getHeaderMap(): Map<String, String> {
         val headerMap = HashMap<String, String>()
-        headerMap["User-Agent"] = App.INSTANCE.getPrefString("user_agent") ?: userAgent
+        headerMap[AppConst.UA_NAME] = App.INSTANCE.getPrefString("user_agent") ?: userAgent
         header?.let {
             val header1 = when {
                 it.startsWith("@js:", true) ->
diff --git a/app/src/main/java/io/legado/app/help/http/AjaxWebView.kt b/app/src/main/java/io/legado/app/help/http/AjaxWebView.kt
index fd364363c..4cd8a3dc5 100644
--- a/app/src/main/java/io/legado/app/help/http/AjaxWebView.kt
+++ b/app/src/main/java/io/legado/app/help/http/AjaxWebView.kt
@@ -9,6 +9,7 @@ import android.os.Message
 import android.text.TextUtils
 import android.webkit.*
 import io.legado.app.App
+import io.legado.app.constant.AppConst
 import org.apache.commons.text.StringEscapeUtils
 import java.lang.ref.WeakReference
 
@@ -101,7 +102,7 @@ class AjaxWebView {
         var javaScript: String? = null
 
         val userAgent: String?
-            get() = this.headerMap?.get("User-Agent")
+            get() = this.headerMap?.get(AppConst.UA_NAME)
 
         val isSniff: Boolean
             get() = !TextUtils.isEmpty(sourceRegex)
diff --git a/app/src/main/java/io/legado/app/help/storage/OldRule.kt b/app/src/main/java/io/legado/app/help/storage/OldRule.kt
index 7418ea6c6..343a54087 100644
--- a/app/src/main/java/io/legado/app/help/storage/OldRule.kt
+++ b/app/src/main/java/io/legado/app/help/storage/OldRule.kt
@@ -1,5 +1,6 @@
 package io.legado.app.help.storage
 
+import io.legado.app.constant.AppConst
 import io.legado.app.data.entities.BookSource
 import io.legado.app.data.entities.rule.*
 import io.legado.app.help.storage.Restore.jsonPath
@@ -131,7 +132,7 @@ object OldRule {
 
     private fun uaToHeader(ua: String?): String? {
         if (ua.isNullOrEmpty()) return null
-        val map = mapOf(Pair("User-Agent", ua))
+        val map = mapOf(Pair(AppConst.UA_NAME, ua))
         return GSON.toJson(map)
     }