diff --git a/src/main/kotlin/com/beust/kobalt/internal/JvmCompiler.kt b/src/main/kotlin/com/beust/kobalt/internal/JvmCompiler.kt
index f833d777..b7471b7c 100644
--- a/src/main/kotlin/com/beust/kobalt/internal/JvmCompiler.kt
+++ b/src/main/kotlin/com/beust/kobalt/internal/JvmCompiler.kt
@@ -22,9 +22,8 @@ class JvmCompiler @Inject constructor(val dependencyManager: DependencyManager)
             : TaskResult {
         File(info.outputDir).mkdirs()
 
-        val allDependencies = arrayListOf<IClasspathDependency>()
-        allDependencies.addAll(info.dependencies)
-        allDependencies.addAll(calculateDependencies(project, context, info.dependencies))
+        val allDependencies = info.dependencies + calculateDependencies(project, context, info.dependencies)
+
         validateClasspath(allDependencies.map { it.jarFile.get().absolutePath })
         return action.compile(info.copy(dependencies = allDependencies))
     }
diff --git a/src/main/kotlin/com/beust/kobalt/kotlin/BuildFileCompiler.kt b/src/main/kotlin/com/beust/kobalt/kotlin/BuildFileCompiler.kt
index 77dfd5fa..6f63cc8f 100644
--- a/src/main/kotlin/com/beust/kobalt/kotlin/BuildFileCompiler.kt
+++ b/src/main/kotlin/com/beust/kobalt/kotlin/BuildFileCompiler.kt
@@ -163,9 +163,8 @@ public class BuildFileCompiler @Inject constructor(@Assisted("buildFiles") val b
     private fun parseBuildScriptJarFile(buildScriptJarFile: File, urls: List<URL>) : BuildScriptInfo {
         val projects = arrayListOf<Project>()
         var stream : InputStream? = null
-        val allUrls = arrayListOf<URL>().plus(urls).plus(arrayOf(
-                buildScriptJarFile.toURI().toURL(),
-                File(files.kobaltJar).toURI().toURL()))
+        val allUrls = (urls + arrayOf(
+                buildScriptJarFile.toURI().toURL()) + File(files.kobaltJar).toURI().toURL())
             .toTypedArray()
         val classLoader = URLClassLoader(allUrls)
 
diff --git a/src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinCompiler.kt b/src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinCompiler.kt
index 9100f93f..3c19785d 100644
--- a/src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinCompiler.kt
+++ b/src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinCompiler.kt
@@ -71,10 +71,7 @@ class KotlinCompiler @Inject constructor(val localRepo : LocalRepo,
                 getKotlinCompilerJar("kotlin-compiler-embeddable"))
             .map { FileDependency(it) }
 
-        val dependencies = arrayListOf<IClasspathDependency>()
-            .plus(compileDependencies)
-            .plus(classpathList)
-            .plus(otherClasspath.map { FileDependency(it)})
+        val dependencies = compileDependencies + classpathList + otherClasspath.map { FileDependency(it)}
         val info = CompilerActionInfo(dependencies, source, outputDir, args)
         return jvmCompiler.doCompile(project, context, compilerAction, info)
     }