diff --git a/build.gradle.kts b/build.gradle.kts
index b063c35..fb6563d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,19 +1,20 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
 plugins {
 	idea
 	`java-library`
 	kotlin("jvm")
 }
 
-val javaVersion: String by ext
-val javaMajorVersion: String by ext
-val kotlinTargetJdk: String by ext
+val javaVersion = extra["javaVersion"] as JavaVersion
+val kotlinTargetJdk = extra["kotlinTargetJdk"] as JvmTarget
 
 java {
 	modularity.inferModulePath.set(true)
+	toolchain.languageVersion.set(JavaLanguageVersion.of(javaVersion.majorVersion))
 }
 
 idea {
-	targetVersion = javaVersion
     module {
         inheritOutputDirs = true
     }
@@ -27,23 +28,29 @@ repositories {
 sourceSets {
 	main {
 		dependencies {
-			implementation(group="org.jetbrains", name="annotations", version="20.1.0")
+			implementation("org.jetbrains:annotations:20.1.0")
 			implementation(project(":pswgcommon"))
-			api(group="me.joshlarson", name="jlcommon-network", version="1.1.2")
-			implementation(group="me.joshlarson", name="websocket", version="0.9.6")
+			api("me.joshlarson:jlcommon-network:1.1.2")
+			implementation("me.joshlarson:websocket:0.9.6")
 		}
 	}
 	test {
 		dependencies {
 			testImplementation(kotlin("stdlib"))
-			testImplementation(group="junit", name="junit", version="4.12")
+			testImplementation("junit:junit:4.12")
 		}
 	}
 }
 
 tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
-	kotlinOptions {
-		jvmTarget = kotlinTargetJdk
+	compilerOptions {
+		jvmTarget.set(kotlinTargetJdk)
 	}
-	destinationDirectory.set(File(destinationDirectory.get().asFile.path.replace("kotlin", "java")))
+}
+
+// Make Kotlin classes visible while javac compiles the JPMS module descriptor.
+tasks.named<JavaCompile>("compileJava") {
+	options.compilerArgumentProviders.add(CommandLineArgumentProvider {
+		listOf("--patch-module", "com.projectswg.forwarder=${sourceSets.main.get().output.asPath}")
+	})
 }