diff --git a/prepare/mock-runtime-for-test/build.gradle.kts b/prepare/mock-runtime-for-test/build.gradle.kts
index 27090813dbe..01b077c37d0 100644
--- a/prepare/mock-runtime-for-test/build.gradle.kts
+++ b/prepare/mock-runtime-for-test/build.gradle.kts
@@ -1,3 +1,4 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 description = "Kotlin Mock Runtime for Tests"
 
@@ -7,12 +8,13 @@ jvmTarget = "1.6"
 javaHome = rootProject.extra["JDK_16"] as String
 
 dependencies {
-//    compile(projectDist(":kotlin-stdlib"))
+    compile(projectDist(":kotlin-stdlib"))
 }
 
 sourceSets {
     "main" {
-//        java.apply {
+        java.apply {
+            srcDir(File(buildDir, "src"))
 //            srcDir(File(rootDir, "core", "runtime.jvm", "src"))
 //                    .include("kotlin/TypeAliases.kt",
 //                             "kotlin/text/TypeAliases.kt")
@@ -21,32 +23,47 @@ sourceSets {
 //                             "kotlin/jvm/JvmVersion.kt",
 //                             "kotlin/util/Standard.kt",
 //                             "kotlin/internal/Annotations.kt")
-//        }
+        }
     }
     "test" {}
 }
 
+val copySources by task<Copy> {
+    from(File(rootDir, "core", "runtime.jvm", "src"))
+            .include("kotlin/TypeAliases.kt",
+                    "kotlin/text/TypeAliases.kt")
+    from(File(rootDir, "libraries", "stdlib", "src"))
+            .include("kotlin/collections/TypeAliases.kt",
+                    "kotlin/jvm/JvmVersion.kt",
+                    "kotlin/util/Standard.kt",
+                    "kotlin/internal/Annotations.kt")
+    into(File(buildDir, "src"))
+}
 
 tasks.withType<JavaCompile> {
     sourceCompatibility = "1.6"
     targetCompatibility = "1.6"
 }
 
+tasks.withType<KotlinCompile> {
+    dependsOn(copySources)
+}
+
 val jar = runtimeJar {
     dependsOn(":core:builtins:serialize")
     from(fileTree("${rootProject.extra["distDir"]}/builtins")) { include("kotlin/**") }
-    dependsOn(":kotlin-stdlib:classes")
-    project(":kotlin-stdlib").let { p ->
-        p.pluginManager.withPlugin("java") {
-            from(p.the<JavaPluginConvention>().sourceSets.getByName("main").output) {
-                include("kotlin/**/TypeAliases*.class",
-                        "kotlin/jvm/JvmVersion.class",
-                        "kotlin/StandardKt*.class",
-                        "kotlin/NotImplementedError*.class",
-                        "kotlin/internal/*.class")
-            }
-        }
-    }
+//    dependsOn(":kotlin-stdlib:classes")
+//    project(":kotlin-stdlib").let { p ->
+//        p.pluginManager.withPlugin("java") {
+//            from(p.the<JavaPluginConvention>().sourceSets.getByName("main").output) {
+//                include("kotlin/**/TypeAliases*.class",
+//                        "kotlin/jvm/JvmVersion.class",
+//                        "kotlin/StandardKt*.class",
+//                        "kotlin/NotImplementedError*.class",
+//                        "kotlin/internal/*.class")
+//            }
+//        }
+//    }
 }
 
 val distDir: String by rootProject.extra