diff --git a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/io/serialization/JceNew.kt b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/io/serialization/JceNew.kt
index ddbf8ac06..d5c7a00b8 100644
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/io/serialization/JceNew.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/io/serialization/JceNew.kt
@@ -191,12 +191,12 @@ private class JceInput(
     /**
      * 跳过 [JceHead] 和对应的数据值, 直到找到 [tag], 否则抛出异常
      */
-    inline fun <R> skipToTagAndUseIfPossibleOrFail(
+    inline fun <R : Any> skipToTagAndUseIfPossibleOrFail(
         tag: Int,
         crossinline message: () -> String = { "tag not found: $tag" },
         crossinline block: (JceHead) -> R
     ): R {
-        return checkNotNull(skipToTagAndUseIfPossibleOrNull(tag, block), message)
+        return checkNotNull<R>(skipToTagAndUseIfPossibleOrNull(tag, block), message)
     }
 
     tailrec fun skipToHeadOrNull(tag: Int): JceHead? {
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/ExternalImageAndroid.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/ExternalImageAndroid.kt
index 328af2a50..285a37cbe 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/ExternalImageAndroid.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/ExternalImageAndroid.kt
@@ -30,8 +30,9 @@ import java.net.URL
 
 
 /**
- * 读取 [BufferedImage] 的属性, 然后构造 [ExternalImage]
+ * 读取 [Bitmap] 的属性, 然后构造 [ExternalImage]
  */
+@Suppress("UNUSED_PARAMETER")
 @Throws(IOException::class)
 fun Bitmap.toExternalImage(formatName: String = "gif"): Nothing {
     TODO()
diff --git a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/SystemDeviceInfo.kt b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/SystemDeviceInfo.kt
index ba502818c..523aef15f 100644
--- a/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/SystemDeviceInfo.kt
+++ b/mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/SystemDeviceInfo.kt
@@ -7,6 +7,8 @@
  * https://github.com/mamoe/mirai/blob/master/LICENSE
  */
 
+@file:Suppress("unused")
+
 package net.mamoe.mirai.utils
 
 import android.annotation.SuppressLint
@@ -18,6 +20,7 @@ import kotlinx.serialization.Serializable
 import kotlinx.serialization.Transient
 import kotlinx.serialization.UnstableDefault
 import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonConfiguration
 import java.io.File
 
 /**
@@ -27,14 +30,17 @@ import java.io.File
 fun File.loadAsDeviceInfo(context: Context): DeviceInfo {
     if (!this.exists() || this.length() == 0L) {
         return SystemDeviceInfo(context).also {
-            this.writeText(Json.plain.stringify(SystemDeviceInfo.serializer(), it))
+            this.writeText(JSON.stringify(SystemDeviceInfo.serializer(), it))
         }
     }
-    return Json.nonstrict.parse(DeviceInfoData.serializer(), this.readText()).also {
+    return JSON.parse(DeviceInfoData.serializer(), this.readText()).also {
         it.context = context
     }
 }
 
+@OptIn(UnstableDefault::class)
+private val JSON = Json(JsonConfiguration.Default)
+
 /**
  * 部分引用指向 [Build].
  * 部分需要权限, 若无权限则会使用默认值.
diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/ExternalImage.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/ExternalImage.kt
index 527c76ec5..b14b5b137 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/ExternalImage.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/ExternalImage.kt
@@ -15,6 +15,7 @@ import io.ktor.utils.io.ByteReadChannel
 import io.ktor.utils.io.core.ByteReadPacket
 import io.ktor.utils.io.core.Input
 import kotlinx.io.InputStream
+import kotlinx.serialization.InternalSerializationApi
 import net.mamoe.mirai.contact.Contact
 import net.mamoe.mirai.contact.Group
 import net.mamoe.mirai.contact.QQ
@@ -69,6 +70,7 @@ class ExternalImage private constructor(
         filename: String
     ) : this(width, height, md5, imageFormat, input as Any, input.remaining, filename)
 
+    @OptIn(InternalSerializationApi::class)
     constructor(
         width: Int,
         height: Int,