diff --git a/build.gradle.kts b/build.gradle.kts
index 1104651..6d3b4dc 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -5,10 +5,6 @@ import java.io.File
 import java.io.FileInputStream
 
 buildscript {
-    repositories {
-        mavenCentral()
-        maven("https://plugins.gradle.org/m2/")
-    }
     dependencies {
         classpath("org.yaml:snakeyaml:1.26")
         classpath("org.jlleitschuh.gradle:ktlint-gradle:10.1.0")
@@ -16,26 +12,25 @@ buildscript {
 }
 
 plugins {
-    id("org.jetbrains.kotlin.jvm") version "1.6.10"
-    id("com.github.johnrengelman.shadow") version "5.2.0"
+    id("org.jetbrains.kotlin.jvm") version "1.8.20"
+    id("com.github.johnrengelman.shadow") version "8.1.1"
     id("org.jlleitschuh.gradle.ktlint") version "10.1.0"
 }
 
-group = "org.kraftwerk28"
-
-val cfg: Map<String, String> = Yaml()
-    .load(FileInputStream("$projectDir/src/main/resources/plugin.yml"))
+val cfg: Map<String, String> = Yaml().run {
+    val pluginFile = FileInputStream("$projectDir/src/main/resources/plugin.yml")
+    load(pluginFile)
+}
 val pluginVersion = cfg.get("version")
 val spigotApiVersion = cfg.get("api-version")
 val retrofitVersion = "2.7.1"
+
+group = "org.kraftwerk28"
 version = pluginVersion as Any
 
 repositories {
     mavenCentral()
-    maven(
-        url = "https://hub.spigotmc.org/nexus/content/repositories/snapshots/"
-    )
-    maven(url = "https://jitpack.io")
+    maven(url = "https://hub.spigotmc.org/nexus/content/repositories/snapshots/")
     maven(url = "https://oss.sonatype.org/content/repositories/snapshots/")
 }
 
@@ -71,9 +66,10 @@ tasks {
         dependsOn("shadowJar")
         finalizedBy("copyArtifacts")
     }
+    withType<JavaCompile> {
+        sourceCompatibility = JavaVersion.VERSION_1_8.toString()
+    }
     withType<KotlinCompile> {
-        kotlinOptions {
-            jvmTarget = "1.8"
-        }
+        kotlinOptions.jvmTarget = "1.8"
     }
 }
diff --git a/src/main/kotlin/org/kraftwerk28/spigot_tg_bridge/TgBot.kt b/src/main/kotlin/org/kraftwerk28/spigot_tg_bridge/TgBot.kt
index b6a9d54..f9dd87d 100644
--- a/src/main/kotlin/org/kraftwerk28/spigot_tg_bridge/TgBot.kt
+++ b/src/main/kotlin/org/kraftwerk28/spigot_tg_bridge/TgBot.kt
@@ -89,7 +89,7 @@ class TgBot(
     }
 
     private fun initPolling() = plugin.launch {
-        loop@while (true) {
+        loop@ while (true) {
             try {
                 api.getUpdates(
                     offset = currentOffset,
@@ -124,19 +124,21 @@ class TgBot(
     }
 
     private suspend fun handleUpdate(update: Update) {
-        // Ignore private message or channel post
-        if (listOf("private", "channel").contains(update.message?.chat?.type))
+        // Accept only these chat types
+        if (!listOf("group", "supergroup").contains(update.message?.chat?.type))
             return
-        val ctx = HandlerContext(
-            update,
-            update.message,
-            update.message?.chat,
-        )
+
+        // Check whether the chat is white-listed in config
+        if (!config.allowedChats.contains(update.message?.chat?.id))
+            return
+
+        val ctx = HandlerContext(update, update.message, update.message?.chat)
         update.message?.text?.let {
             commandRegex?.matchEntire(it)?.groupValues?.let { matchList ->
-                commandMap[matchList[1]]?.run {
-                    val args = matchList[2].split("\\s+".toRegex())
-                    this(ctx.copy(commandArgs = args))
+                commandMap[matchList[1]]?.let { handler ->
+                    val commandArgs = matchList[2].split("""\s+""".toRegex())
+                    val handlerContext = ctx.copy(commandArgs = commandArgs)
+                    handler(handlerContext)
                 }
             } ?: run {
                 onTextHandler(ctx)
@@ -231,9 +233,9 @@ class TgBot(
             api.sendMessage(ctx.message!!.chat.id, "No linked users.")
         } else {
             val text = "<b>Linked users:</b>\n" +
-                linkedUsers.mapIndexed { i, dbUser ->
-                    "${i + 1}. ${dbUser.fullName()}"
-                }.joinToString("\n")
+                    linkedUsers.mapIndexed { i, dbUser ->
+                        "${i + 1}. ${dbUser.fullName()}"
+                    }.joinToString("\n")
             api.sendMessage(ctx.message!!.chat.id, text)
         }
     }
diff --git a/src/main/resources/plugin.yml b/src/main/resources/plugin.yml
index 9b08d6c..fe4a254 100644
--- a/src/main/resources/plugin.yml
+++ b/src/main/resources/plugin.yml
@@ -1,5 +1,5 @@
 name: SpigotTGBridge
-version: "0.20.1"
+version: "0.20.2"
 api-version: "1.15"
 main: org.kraftwerk28.spigot_tg_bridge.Plugin
 description: Telegram <-> Minecraft communication plugin for Spigot.