diff --git a/backend.native/tests/build.gradle b/backend.native/tests/build.gradle
index b29a15876b7..3b310e10124 100644
--- a/backend.native/tests/build.gradle
+++ b/backend.native/tests/build.gradle
@@ -146,7 +146,7 @@ def tasksOf(Closure<Task> filter) {
 }
 
 run {
-    def tasks = tasksOf { it instanceof RunKonanTest && !(it instanceof RunStdlibTest) }
+    def tasks = tasksOf { it instanceof KonanTest && it.inDevelopersRun }
     dependsOn(tasks)
 }
 
@@ -2419,10 +2419,13 @@ if (isMac()) {
 
 task jsinterop_math(type: RunStandaloneKonanTest) {
     doFirst {
+        def jsinteropScript = isWindows() ? "jsinterop.bat" : "jsinterop"
+        def jsinterop = "$distDir/bin/$jsinteropScript"
         // TODO: We probably need a NativeInteropPlugin for jsinterop?
-        "jsinterop -pkg kotlinx.interop.wasm.math -o $buildDir/jsmath -target wasm32".execute()
+        "$jsinterop -pkg kotlinx.interop.wasm.math -o $buildDir/jsmath -target wasm32".execute().waitFor()
 
     }
+    dependsOn ':wasm32PlatformLibs'
     disabled = (project.testTarget != 'wasm32')
     goldValue = "e = 2.718281828459045, pi = 3.141592653589793, sin(pi) = 1.2246467991473532E-16, sin(pi/2) = 1.0, ln(1) = 0.0, ln(e) = 1.0\n"
     source = "jsinterop/math.kt"
diff --git a/buildSrc/plugins/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy b/buildSrc/plugins/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy
index d9ea1ecd248..d9045a0e19f 100644
--- a/buildSrc/plugins/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy
+++ b/buildSrc/plugins/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy
@@ -28,6 +28,8 @@ import javax.inject.Inject
 import java.util.regex.Pattern
 
 abstract class KonanTest extends JavaExec {
+    public boolean inDevelopersRun = false
+
     public String source
     def targetManager = new TargetManager(project.testTarget)
     def target = targetManager.target
@@ -390,6 +392,8 @@ class BuildKonanTest extends ExtKonanTest {
  * Runs test built with Konan's TestRunner
  */
 class RunKonanTest extends ExtKonanTest {
+    public def inDevelopersRun = true
+
     public def buildTaskName = 'buildKonanTests'
     public def runnerLogger = Logger.SILENT
     public def useFilter = true
@@ -437,6 +441,7 @@ class RunKonanTest extends ExtKonanTest {
 }
 
 class RunStdlibTest extends RunKonanTest {
+    public def inDevelopersRun = false
 
     RunStdlibTest() {
         super('buildKonanStdlibTests')
@@ -447,6 +452,8 @@ class RunStdlibTest extends RunKonanTest {
  * Compiles and executes test as a standalone binary
  */
 class RunStandaloneKonanTest extends KonanTest {
+    public def inDevelopersRun = true
+
     void compileTest(List<String> filesToCompile, String exe) {
         runCompiler(filesToCompile, exe, flags?:[])
     }
@@ -521,6 +528,8 @@ class RunInteropKonanTest extends KonanTest {
 }
 
 class LinkKonanTest extends KonanTest {
+    public def inDevelopersRun = true
+
     protected String lib
 
     void compileTest(List<String> filesToCompile, String exe) {
@@ -564,6 +573,7 @@ class DynamicKonanTest extends KonanTest {
     }
 }
 class RunExternalTestGroup extends RunStandaloneKonanTest {
+    def inDevelopersRun = false
 
     def groupDirectory = "."
     def outputSourceSetName = "testOutputExternal"
diff --git a/runtime/src/main/cpp/ReturnSlot.cpp b/runtime/src/main/cpp/ReturnSlot.cpp
index ef47a2cbf95..2c5ac47787e 100644
--- a/runtime/src/main/cpp/ReturnSlot.cpp
+++ b/runtime/src/main/cpp/ReturnSlot.cpp
@@ -25,10 +25,12 @@ THREAD_LOCAL_VARIABLE long long storage;
 
 extern "C" {
 
+RUNTIME_USED
 KDouble ReturnSlot_getDouble() {
   return *reinterpret_cast<KDouble*>(&::storage);
 }
 
+RUNTIME_USED
 void ReturnSlot_setDouble(KInt upper, KInt lower) {
   reinterpret_cast<KInt*>(&::storage)[0] = lower;
   reinterpret_cast<KInt*>(&::storage)[1] = upper;