diff --git a/libraries/stdlib/jdk7/build.gradle b/libraries/stdlib/jdk7/build.gradle
index 1e56622188d..361e0fda382 100644
--- a/libraries/stdlib/jdk7/build.gradle
+++ b/libraries/stdlib/jdk7/build.gradle
@@ -90,6 +90,7 @@ compileTestKotlin {
             "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
             "-Xopt-in=kotlin.ExperimentalStdlibApi",
             "-Xopt-in=kotlin.io.path.ExperimentalPathApi",
+            "-Xcommon-sources=${fileTree('../test').join(',')}",
     ]
 }
 
diff --git a/libraries/stdlib/jdk8/build.gradle b/libraries/stdlib/jdk8/build.gradle
index e59fbc30e3b..a5e45269b44 100644
--- a/libraries/stdlib/jdk8/build.gradle
+++ b/libraries/stdlib/jdk8/build.gradle
@@ -82,6 +82,7 @@ compileTestKotlin {
             "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
             "-Xopt-in=kotlin.ExperimentalStdlibApi",
             "-Xopt-in=kotlin.io.path.ExperimentalPathApi",
+            "-Xcommon-sources=${fileTree('../test').join(',')}",
     ]
 }
 
diff --git a/libraries/stdlib/js-ir/build.gradle.kts b/libraries/stdlib/js-ir/build.gradle.kts
index 47ee64c00ba..1d0629ebff2 100644
--- a/libraries/stdlib/js-ir/build.gradle.kts
+++ b/libraries/stdlib/js-ir/build.gradle.kts
@@ -149,6 +149,15 @@ val compileKotlinJs by tasks.existing(KotlinCompile::class) {
     kotlinOptions.freeCompilerArgs += "-Xir-module-name=kotlin"
 }
 
+
+val compileTestKotlinJs by tasks.existing(KotlinCompile::class) {
+    doFirst {
+        // Note: common test sources are copied to the actual source directory by commonMainSources task,
+        // so can't do this at configuration time:
+        kotlinOptions.freeCompilerArgs += "-Xcommon-sources=${kotlin.sourceSets["commonTest"].kotlin.joinToString(",")}"
+    }
+}
+
 val packFullRuntimeKLib by tasks.registering(Jar::class) {
     dependsOn(compileKotlinJs)
     from(buildDir.resolve("classes/kotlin/js/main"))