diff --git a/build.gradle b/build.gradle
index ecd6c30..06ee9ca 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,13 +8,13 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath group: 'org.jetbrains.kotlin', name: 'kotlin-gradle-plugin', version: '2.0.10-RC'
+        classpath group: 'org.jetbrains.kotlin', name: 'kotlin-gradle-plugin', version: '1.9.25'
         classpath "org.jetbrains.dokka:dokka-gradle-plugin:1.9.20"
     }
 }
 
 plugins {
-    id 'org.jetbrains.kotlin.jvm' version '2.0.10-RC'
+    id 'org.jetbrains.kotlin.jvm' version '1.9.25'
     id 'io.codearte.nexus-staging' version '0.20.0'
     id "de.marcphilipp.nexus-publish" version '0.2.0'
 }
diff --git a/gradle.properties b/gradle.properties
index fc695e3..13e74dc 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
 kotlin.code.style=official
 javaVersion=1.8
-kotlinVersion=2.0.10-RC
+kotlinVersion=1.9.25
 org.gradle.jvmargs=-Xms4g
diff --git a/mccoroutine-bungeecord-sample/build.gradle.kts b/mccoroutine-bungeecord-sample/build.gradle.kts
index fbbe793..a1e8e55 100644
--- a/mccoroutine-bungeecord-sample/build.gradle.kts
+++ b/mccoroutine-bungeecord-sample/build.gradle.kts
@@ -36,8 +36,8 @@ dependencies {
     implementation(project(":mccoroutine-bungeecord-core"))
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.9.0-RC")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.3.9")
 
     compileOnly("net.md-5:bungeecord-api:1.16-R0.5-SNAPSHOT")
     testImplementation("net.md-5:bungeecord-api:1.16-R0.5-SNAPSHOT")
diff --git a/mccoroutine-fabric-api/build.gradle.kts b/mccoroutine-fabric-api/build.gradle.kts
index 79ae17c..73fadb6 100644
--- a/mccoroutine-fabric-api/build.gradle.kts
+++ b/mccoroutine-fabric-api/build.gradle.kts
@@ -1,3 +1,5 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 repositories {
     maven {
         url = uri("https://maven.fabricmc.net")
@@ -9,12 +11,18 @@ repositories {
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(8))
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}
+
+tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions {
+        jvmTarget = "17"
     }
 }
 
 dependencies {
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("net.fabricmc:fabric-loader:0.14.13")
     compileOnly("net.fabricmc.fabric-api:fabric-api:0.73.0+1.19.3")
     compileOnly("com.mojang:brigadier:1.0.18")
diff --git a/mccoroutine-fabric-core/build.gradle.kts b/mccoroutine-fabric-core/build.gradle.kts
index afe023c..623ed0f 100644
--- a/mccoroutine-fabric-core/build.gradle.kts
+++ b/mccoroutine-fabric-core/build.gradle.kts
@@ -1,3 +1,5 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 repositories {
     maven {
         url = uri("https://maven.fabricmc.net")
@@ -9,17 +11,23 @@ repositories {
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(8))
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}
+
+tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions {
+        jvmTarget = "17"
     }
 }
 
 dependencies {
     implementation(project(":mccoroutine-fabric-api"))
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("net.fabricmc:fabric-loader:0.14.13")
     compileOnly("net.fabricmc.fabric-api:fabric-api:0.73.0+1.19.3")
     testImplementation("com.mojang:brigadier:1.0.18")
     testImplementation("net.fabricmc:fabric-loader:0.14.13")
     testImplementation("net.fabricmc.fabric-api:fabric-api:0.73.0+1.19.3")
-    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
 }
diff --git a/mccoroutine-folia-api/build.gradle.kts b/mccoroutine-folia-api/build.gradle.kts
index af5f11f..4eb221e 100644
--- a/mccoroutine-folia-api/build.gradle.kts
+++ b/mccoroutine-folia-api/build.gradle.kts
@@ -20,5 +20,5 @@ tasks.withType<KotlinCompile>().configureEach {
 
 dependencies {
     compileOnly("org.spigotmc:spigot-api:1.16.3-R0.1-SNAPSHOT")
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
 }
diff --git a/mccoroutine-folia-core/build.gradle.kts b/mccoroutine-folia-core/build.gradle.kts
index 6d6a8a0..2397776 100644
--- a/mccoroutine-folia-core/build.gradle.kts
+++ b/mccoroutine-folia-core/build.gradle.kts
@@ -22,9 +22,9 @@ tasks.withType<KotlinCompile>().configureEach {
 dependencies {
     implementation(project(":mccoroutine-folia-api"))
 
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("dev.folia:folia-api:1.20.1-R0.1-20230615.235213-1")
 
-    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     testImplementation("dev.folia:folia-api:1.20.1-R0.1-20230615.235213-1")
 }
diff --git a/mccoroutine-folia-sample/build.gradle.kts b/mccoroutine-folia-sample/build.gradle.kts
index d495c48..5288933 100644
--- a/mccoroutine-folia-sample/build.gradle.kts
+++ b/mccoroutine-folia-sample/build.gradle.kts
@@ -43,8 +43,8 @@ dependencies {
     implementation(project(":mccoroutine-folia-core"))
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.9.0-RC")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.3.9")
 
     compileOnly("dev.folia:folia-api:1.20.1-R0.1-20230615.235213-1")
 
diff --git a/mccoroutine-minestom-api/build.gradle.kts b/mccoroutine-minestom-api/build.gradle.kts
index b4e4c4c..23c79c2 100644
--- a/mccoroutine-minestom-api/build.gradle.kts
+++ b/mccoroutine-minestom-api/build.gradle.kts
@@ -19,8 +19,8 @@ tasks.withType<KotlinCompile>().configureEach {
 }
 
 dependencies {
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("net.minestom:minestom-snapshots:6fc64e3a5d")
-    implementation("dev.hollowcube:minestom-ce-extensions:1.2.0")
+    compileOnly("dev.hollowcube:minestom-ce-extensions:1.2.0")
     testImplementation("net.minestom:minestom-snapshots:6fc64e3a5d")
 }
diff --git a/mccoroutine-minestom-core/build.gradle.kts b/mccoroutine-minestom-core/build.gradle.kts
index 3cde23e..e9de03e 100644
--- a/mccoroutine-minestom-core/build.gradle.kts
+++ b/mccoroutine-minestom-core/build.gradle.kts
@@ -22,9 +22,9 @@ dependencies {
     implementation(project(":mccoroutine-minestom-api"))
 
     compileOnly("net.kyori:adventure-text-logger-slf4j:4.12.0")
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     implementation("net.minestom:minestom-snapshots:6fc64e3a5d")
-    implementation("dev.hollowcube:minestom-ce-extensions:1.2.0")
     testImplementation("net.minestom:minestom-snapshots:6fc64e3a5d")
-    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("dev.hollowcube:minestom-ce-extensions:1.2.0")
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
 }
diff --git a/mccoroutine-minestom-sample/build.gradle.kts b/mccoroutine-minestom-sample/build.gradle.kts
index 195e1cf..5121c70 100644
--- a/mccoroutine-minestom-sample/build.gradle.kts
+++ b/mccoroutine-minestom-sample/build.gradle.kts
@@ -28,10 +28,10 @@ dependencies {
     implementation(project(":mccoroutine-minestom-core"))
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.9.0-RC")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.3.9")
 
-    implementation("dev.hollowcube:minestom-ce-extensions:1.2.0")
+    compileOnly("dev.hollowcube:minestom-ce-extensions:1.2.0")
     implementation("net.minestom:minestom-snapshots:6fc64e3a5d")
 }
 
diff --git a/mccoroutine-sponge-sample/build.gradle.kts b/mccoroutine-sponge-sample/build.gradle.kts
index c7eaac6..e19e10b 100644
--- a/mccoroutine-sponge-sample/build.gradle.kts
+++ b/mccoroutine-sponge-sample/build.gradle.kts
@@ -36,8 +36,8 @@ dependencies {
     implementation(project(":mccoroutine-sponge-core"))
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.9.0-RC")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.2.2")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.2.2")
 
     compileOnly("com.google.guava:guava:23.0")
     compileOnly("org.spongepowered:spongeapi:7.2.0")
diff --git a/mccoroutine-velocity-api/build.gradle.kts b/mccoroutine-velocity-api/build.gradle.kts
index f5258df..3190d7e 100644
--- a/mccoroutine-velocity-api/build.gradle.kts
+++ b/mccoroutine-velocity-api/build.gradle.kts
@@ -19,7 +19,7 @@ tasks.withType<KotlinCompile>().configureEach {
 }
 
 dependencies {
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("com.velocitypowered:velocity-api:3.0.1")
     testImplementation("com.velocitypowered:velocity-api:3.0.1")
 }
diff --git a/mccoroutine-velocity-core/build.gradle.kts b/mccoroutine-velocity-core/build.gradle.kts
index 7e01bd4..1a8eace 100644
--- a/mccoroutine-velocity-core/build.gradle.kts
+++ b/mccoroutine-velocity-core/build.gradle.kts
@@ -21,11 +21,11 @@ tasks.withType<KotlinCompile>().configureEach {
 dependencies {
     implementation(project(":mccoroutine-velocity-api"))
 
-    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    compileOnly("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     compileOnly("com.velocitypowered:velocity-api:3.0.1")
     compileOnly("org.apache.logging.log4j:log4j-core:2.17.2")
 
-    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
     testImplementation(files("lib/velocity.jar"))
     testImplementation("com.velocitypowered:velocity-api:3.0.1")
 }
diff --git a/mccoroutine-velocity-sample/build.gradle.kts b/mccoroutine-velocity-sample/build.gradle.kts
index fccc579..b1f14ad 100644
--- a/mccoroutine-velocity-sample/build.gradle.kts
+++ b/mccoroutine-velocity-sample/build.gradle.kts
@@ -2,13 +2,9 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     id("com.github.johnrengelman.shadow") version ("8.1.1")
-    id("org.jetbrains.kotlin.kapt")
+    id("org.jetbrains.kotlin.kapt") // Required to generate the velocity-plugin.json file.
 }
 
-
-// Required to generate the velocity-plugin.json file.
-//apply plugin: 'kotlin-kapt'
-
 java {
     toolchain {
         languageVersion = JavaLanguageVersion.of(11)
@@ -42,8 +38,8 @@ dependencies {
     implementation(project(":mccoroutine-velocity-core"))
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0-RC")
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.9.0-RC")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:1.3.9")
 
     compileOnly("com.velocitypowered:velocity-api:3.0.1")
     kapt("com.velocitypowered:velocity-api:3.0.1")