diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/descriptors/DescriptorUtils.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/descriptors/DescriptorUtils.kt
index 0eaa9ed4e6b..3bfaddd42d9 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/descriptors/DescriptorUtils.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/descriptors/DescriptorUtils.kt
@@ -74,9 +74,14 @@ internal fun <T : CallableMemberDescriptor> T.resolveFakeOverride(): T {
 
 private val intrinsicAnnotation = FqName("konan.internal.Intrinsic")
 
-// TODO: check it is external?
-internal val CallableDescriptor.isIntrinsic: Boolean
-    get() = this.annotations.findAnnotation(intrinsicAnnotation) != null
+internal val FunctionDescriptor.isIntrinsic: Boolean
+    get() = when {
+        this.annotations.hasAnnotation(intrinsicAnnotation) -> {
+            check(isExternal, { "Intrinsic function $name should be external" })
+            true
+        }
+        else -> false
+    }
 
 private val intrinsicTypes = setOf(
         "kotlin.Boolean", "kotlin.Char",
diff --git a/runtime/src/main/kotlin/konan/internal/Coroutines.kt b/runtime/src/main/kotlin/konan/internal/Coroutines.kt
index 1f9666a4cbe..ce8ea52f74a 100644
--- a/runtime/src/main/kotlin/konan/internal/Coroutines.kt
+++ b/runtime/src/main/kotlin/konan/internal/Coroutines.kt
@@ -21,11 +21,11 @@ import kotlin.coroutines.experimental.intrinsics.*
 
 @Intrinsic
 @PublishedApi
-internal fun <T> getContinuation(): Continuation<T> = throw AssertionError("Call to getContinuation should've been lowered")
+internal external fun <T> getContinuation(): Continuation<T> = throw AssertionError("Call to getContinuation should've been lowered")
 
 @Intrinsic
 @PublishedApi
-internal suspend fun <T> returnIfSuspended(@Suppress("UNUSED_PARAMETER") argument: Any?): T
+internal external suspend fun <T> returnIfSuspended(@Suppress("UNUSED_PARAMETER") argument: Any?): T
         = throw AssertionError("Call to returnIfSuspended should've been lowered")
 
 // Single-threaded continuation.