diff --git a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/ContactImpl.kt b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/ContactImpl.kt
index a933dcfdf..5cad965a2 100644
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/ContactImpl.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/ContactImpl.kt
@@ -227,9 +227,9 @@ internal class MemberImpl(
 
     override val bot: QQAndroidBot get() = qq.bot
 
-    override suspend fun mute(durationSeconds: Int): Boolean {
+    override suspend fun mute(durationSeconds: Int) {
         if (group.botPermission != MemberPermission.OWNER && (!group.botPermission.isOperator() || this.isOperator())) {
-            return false
+            throw PermissionDeniedException()
         }
 
         bot.network.run {
@@ -243,12 +243,11 @@ internal class MemberImpl(
 
         @Suppress("RemoveRedundantQualifierName") // or unresolved reference
         net.mamoe.mirai.event.events.MemberMuteEvent(this@MemberImpl, durationSeconds, null).broadcast()
-        return true
     }
 
-    override suspend fun unmute(): Boolean {
+    override suspend fun unmute() {
         if (group.botPermission != MemberPermission.OWNER && (!group.botPermission.isOperator() || this.isOperator())) {
-            return false
+            throw PermissionDeniedException()
         }
 
         bot.network.run {
@@ -262,16 +261,15 @@ internal class MemberImpl(
 
         @Suppress("RemoveRedundantQualifierName") // or unresolved reference
         net.mamoe.mirai.event.events.MemberUnmuteEvent(this@MemberImpl, null).broadcast()
-        return true
     }
 
-    override suspend fun kick(message: String): Boolean {
+    override suspend fun kick(message: String) {
         if (group.botPermission != MemberPermission.OWNER && (!group.botPermission.isOperator() || this.isOperator())) {
-            return false
+            throw PermissionDeniedException()
         }
 
         bot.network.run {
-            return TroopManagement.Kick(
+            TroopManagement.Kick(
                 client = bot.client,
                 member = this@MemberImpl,
                 message = message
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
index c705ef844..8813ecdd7 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Group.kt
@@ -16,6 +16,7 @@ import net.mamoe.mirai.data.MemberInfo
 import net.mamoe.mirai.event.events.*
 import net.mamoe.mirai.utils.MiraiExperimentalAPI
 import kotlin.jvm.JvmName
+import kotlin.jvm.JvmStatic
 
 /**
  * 群. 在 QQ Android 中叫做 "Troop"
@@ -145,6 +146,7 @@ interface Group : Contact, CoroutineScope {
         /**
          * by @kar98k
          */
+        @JvmStatic
         fun calculateGroupUinByGroupCode(groupCode: Long): Long {
             var left: Long = groupCode / 1000000L
 
@@ -161,6 +163,7 @@ interface Group : Contact, CoroutineScope {
             return left * 1000000L + groupCode % 1000000L
         }
 
+        @JvmStatic
         fun calculateGroupCodeByGroupUin(groupUin: Long): Long {
             var left: Long = groupUin / 1000000L
 
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
index 2e8f9b859..66e8f2ca3 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Member.kt
@@ -35,20 +35,22 @@ interface Member : QQ, Contact {
     /**
      * 群名片. 可能为空. 修改时将会触发事件
      *
-     * 在修改时将会异步上传至服务器. 无权限修改时将会抛出异常 [PermissionDeniedException]
+     * 在修改时将会异步上传至服务器.
      *
      * @see [groupCardOrNick] 获取非空群名片或昵称
      *
      * @see MemberCardChangeEvent 群名片被管理员, 自己或 [Bot] 改动事件
+     * @throws PermissionDeniedException 无权限修改时
      */
     var nameCard: String
 
     /**
      * 群头衔
      *
-     * 在修改时将会异步上传至服务器. 无权限修改时将会抛出异常 [PermissionDeniedException]
+     * 在修改时将会异步上传至服务器.
      *
      * @see MemberSpecialTitleChangeEvent 群名片被管理员, 自己或 [Bot] 改动事件
+     * @throws PermissionDeniedException 无权限修改时
      */
     var specialTitle: String
 
@@ -63,22 +65,25 @@ interface Member : QQ, Contact {
      * @see Int.daysToSeconds
      *
      * @see MemberMuteEvent 成员被禁言事件
+     * @throws PermissionDeniedException 无权限修改时
      */
-    suspend fun mute(durationSeconds: Int): Boolean
+    suspend fun mute(durationSeconds: Int)
 
     /**
-     * 解除禁言. 机器人无权限时返回 `false`.
+     * 解除禁言.
      *
      * @see MemberUnmuteEvent 成员被取消禁言事件.
+     * @throws PermissionDeniedException 无权限修改时
      */
-    suspend fun unmute(): Boolean
+    suspend fun unmute()
 
     /**
-     * 踢出该成员. 机器人无权限时返回 `false`.
+     * 踢出该成员.
      *
      * @see MemberLeaveEvent.Kick 成员被踢出事件.
+     * @throws PermissionDeniedException 无权限修改时
      */
-    suspend fun kick(message: String = ""): Boolean
+    suspend fun kick(message: String = "")
 
     /**
      * 当且仅当 `[other] is [Member] && [other].id == this.id && [other].group == this.group` 时为 true
@@ -94,10 +99,10 @@ interface Member : QQ, Contact {
 val Member.groupCardOrNick: String get() = this.nameCard.takeIf { it.isNotEmpty() } ?: this.nick
 
 @ExperimentalTime
-suspend inline fun Member.mute(duration: Duration): Boolean {
+suspend inline fun Member.mute(duration: Duration) {
     require(duration.inDays <= 30) { "duration must be at most 1 month" }
     require(duration.inSeconds > 0) { "duration must be greater than 0 second" }
-    return this.mute(duration.inSeconds.toInt())
+    this.mute(duration.inSeconds.toInt())
 }
 
 suspend inline fun Member.mute(durationSeconds: Long) = this.mute(durationSeconds.toInt())
\ No newline at end of file