diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.kt b/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.kt
index c7ad3dddb95..501471682a1 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.kt
@@ -8,10 +8,10 @@ external class <!NESTED_JS_MODULE_PROHIBITED!>A<!>
 external <!NESTED_JS_MODULE_PROHIBITED!>object B<!>
 
 <!NESTED_JS_MODULE_PROHIBITED!>@JsModule("foo")
-external fun foo()<!> = 23
+external fun foo(): Int<!>
 
 <!NESTED_JS_MODULE_PROHIBITED!>@JsModule("bar")
-external val bar<!> = 42
+external val bar: Int<!>
 
 <!NESTED_JS_MODULE_PROHIBITED!>@JsNonModule
-external val baz<!> = 99
\ No newline at end of file
+external val baz: Int<!>
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.txt b/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.txt
index 7b0f5f3f911..11dee24c214 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/module/nestedProhibited.txt
@@ -1,8 +1,8 @@
 package
 
 package foo {
-    @kotlin.js.JsModule(import = "bar") public external val bar: kotlin.Int = 42
-    @kotlin.js.JsNonModule public external val baz: kotlin.Int = 99
+    @kotlin.js.JsModule(import = "bar") public external val bar: kotlin.Int
+    @kotlin.js.JsNonModule public external val baz: kotlin.Int
     @kotlin.js.JsModule(import = "foo") public external fun foo(): kotlin.Int
 
     @kotlin.js.JsModule(import = "A") public external final class A {
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/body.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/body.kt
new file mode 100644
index 00000000000..c8008fc6734
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/body.kt
@@ -0,0 +1,30 @@
+external fun foo(): Int = noImpl
+
+external fun bar(): Unit {
+    noImpl
+}
+
+external fun baz(): Int = <!WRONG_BODY_OF_EXTERNAL_DECLARATION!>23<!>
+
+external fun f(x: Int, y: String = noImpl): Unit
+
+external fun g(x: Int, y: String = <!WRONG_BODY_OF_EXTERNAL_DECLARATION!>""<!>): Unit
+
+external var a: Int
+    get() = noImpl
+    set(value) {
+        noImpl
+    }
+
+external val b: Int
+    get() = <!WRONG_BODY_OF_EXTERNAL_DECLARATION!>23<!>
+
+external val c: Int = noImpl
+
+external val d: Int = <!WRONG_BODY_OF_EXTERNAL_DECLARATION!>23<!>
+
+external class C {
+    fun foo(): Int = noImpl
+
+    fun bar(): Int = <!WRONG_BODY_OF_EXTERNAL_DECLARATION!>23<!>
+}
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/body.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/body.txt
new file mode 100644
index 00000000000..063848a5b8d
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/body.txt
@@ -0,0 +1,20 @@
+package
+
+public external var a: kotlin.Int
+public external val b: kotlin.Int
+public external val c: kotlin.Int
+public external val d: kotlin.Int = 23
+public external fun bar(): kotlin.Unit
+public external fun baz(): kotlin.Int
+public external fun f(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.String = ...): kotlin.Unit
+public external fun foo(): kotlin.Int
+public external fun g(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.String = ...): kotlin.Unit
+
+public external final class C {
+    public constructor C()
+    public final fun bar(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.kt
index 2964529646b..ac289e09442 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.kt
@@ -2,36 +2,36 @@
 
 external class A {
     @nativeGetter
-    fun get(a: String): Any? = null
+    fun get(a: String): Any? = noImpl
 
     @nativeGetter
-    fun take(a: Number): String? = null
+    fun take(a: Number): String? = noImpl
 
     @nativeGetter
-    fun foo(a: Double): String? = null
+    fun foo(a: Double): String? = noImpl
 
     companion object {
         @nativeGetter
-        fun get(a: String): Any? = null
+        fun get(a: String): Any? = noImpl
 
         @nativeGetter
-        fun take(a: Number): String? = null
+        fun take(a: Number): String? = noImpl
 
         @nativeGetter
-        fun foo(a: Double): String? = null
+        fun foo(a: Double): String? = noImpl
     }
 }
 
 external class B {
     <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
-    val foo = 0
+    val foo: Int = noImpl
 
     <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
     object Obj1 {}
 
     companion object {
         <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
-        val foo = 0
+        val foo: Int = noImpl
 
         <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
         object Obj2 {}
@@ -40,18 +40,18 @@ external class B {
 
 external class C {
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeGetter
-    fun get(): Any?<!> = null
+    fun get(): Any?<!> = noImpl
 
     @nativeGetter
-    fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = null
+    fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = noImpl
 
     @nativeGetter
-    fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) {}
+    fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) { noImpl }
 
     @nativeGetter
-    fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = 0
+    fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = noImpl
 
     @nativeGetter
-    fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = "foo"<!>): Int? = 0
+    fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = noImpl<!>): Int? = noImpl
 
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.txt
index 1a14273103c..ae27662ce7d 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNativeClassMembers.txt
@@ -22,14 +22,14 @@ public external final class A {
 
 public external final class B {
     public constructor B()
-    @kotlin.js.nativeGetter public final val foo: kotlin.Int = 0
+    @kotlin.js.nativeGetter public final val foo: kotlin.Int
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
     public companion object Companion {
         private constructor Companion()
-        @kotlin.js.nativeGetter public final val foo: kotlin.Int = 0
+        @kotlin.js.nativeGetter public final val foo: kotlin.Int
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.kt
index ce813f9e666..cd96b1cdcf3 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.kt
@@ -4,36 +4,36 @@ external class A {
     class B {
         class A {
             @nativeGetter
-            fun get(a: String): Any? = null
+            fun get(a: String): Any? = noImpl
 
             @nativeGetter
-            fun take(a: Number): String? = null
+            fun take(a: Number): String? = noImpl
 
             @nativeGetter
-            fun foo(a: Double): String? = null
+            fun foo(a: Double): String? = noImpl
 
             companion object {
                 @nativeGetter
-                fun get(a: String): Any? = null
+                fun get(a: String): Any? = noImpl
 
                 @nativeGetter
-                fun take(a: Number): String? = null
+                fun take(a: Number): String? = noImpl
 
                 @nativeGetter
-                fun foo(a: Double): String? = null
+                fun foo(a: Double): String? = noImpl
             }
         }
 
         class B {
             <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
-            val foo = 0
+            val foo: Int = noImpl
 
             <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
             object Obj1 {}
 
             companion object {
                 <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
-                val foo = 0
+                val foo: Int = noImpl
 
                 <!WRONG_ANNOTATION_TARGET!>@nativeGetter<!>
                 object Obj2 {}
@@ -42,53 +42,36 @@ external class A {
 
         class C {
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeGetter
-            fun get(): Any?<!> = null
+            fun get(): Any?<!> = noImpl
 
             @nativeGetter
-            fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = null
+            fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = noImpl
 
             @nativeGetter
-            fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) {}
+            fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) { noImpl }
 
             @nativeGetter
-            fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = 0
+            fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = noImpl
 
             @nativeGetter
-            fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Number = 1.1<!>): Int? = 0
+            fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Number = noImpl<!>): Int? = noImpl
         }
 
         object obj {
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeGetter
-            fun get(): Any?<!> = null
+            fun get(): Any?<!> = noImpl
 
             @nativeGetter
-            fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = null
+            fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = noImpl
 
             @nativeGetter
-            fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) {}
+            fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) { noImpl }
 
             @nativeGetter
-            fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = 0
+            fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = noImpl
 
             @nativeGetter
-            fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = "foo"<!>): Int? = 0
-        }
-
-        val anonymous = object {
-            <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeGetter
-            fun get(): Any?<!> = null
-
-            @nativeGetter
-            fun get(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any? = null
-
-            @nativeGetter
-            fun <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>foo<!>(a: Int) {}
-
-            @nativeGetter
-            fun bar(a: String): <!NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE!>Int<!> = 0
-
-            @nativeGetter
-            fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = "foo"<!>): Int? = 0
+            fun baz(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = noImpl<!>): Int? = noImpl
         }
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.txt
index 7493ed41496..4e233004150 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeGetter/onNestedDeclarationsInsideNativeClass.txt
@@ -8,7 +8,6 @@ public external final class A {
 
     public final class B {
         public constructor B()
-        public final val anonymous: kotlin.Any
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
@@ -35,14 +34,14 @@ public external final class A {
 
         public final class B {
             public constructor B()
-            @kotlin.js.nativeGetter public final val foo: kotlin.Int = 0
+            @kotlin.js.nativeGetter public final val foo: kotlin.Int
             public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             public companion object Companion {
                 private constructor Companion()
-                @kotlin.js.nativeGetter public final val foo: kotlin.Int = 0
+                @kotlin.js.nativeGetter public final val foo: kotlin.Int
                 public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.kt
index 4b352e132b9..bc4cd9e9f49 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.kt
@@ -2,26 +2,26 @@
 
 external class A {
     @nativeInvoke
-    fun foo() {}
+    fun foo() {noImpl}
 
     @nativeInvoke
-    fun invoke(a: String): Int = 0
+    fun invoke(a: String): Int = noImpl
 
     <!WRONG_ANNOTATION_TARGET!>@nativeInvoke<!>
-    val foo = 0
+    val foo: Int = noImpl
 
     <!WRONG_ANNOTATION_TARGET!>@nativeInvoke<!>
     object Obj1 {}
 
     companion object {
         @nativeInvoke
-        fun foo() {}
+        fun foo() { noImpl }
 
         @nativeInvoke
-        fun invoke(a: String): Int = 0
+        fun invoke(a: String): Int = noImpl
 
         <!WRONG_ANNOTATION_TARGET!>@nativeInvoke<!>
-        val foo = 0
+        val foo: Int = noImpl
 
         <!WRONG_ANNOTATION_TARGET!>@nativeInvoke<!>
         object Obj2 {}
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.txt
index 7385d06aeff..588cf2cb830 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNativeClassMembers.txt
@@ -2,7 +2,7 @@ package
 
 public external final class A {
     public constructor A()
-    @kotlin.js.nativeInvoke public final val foo: kotlin.Int = 0
+    @kotlin.js.nativeInvoke public final val foo: kotlin.Int
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     @kotlin.js.nativeInvoke public final fun foo(): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
@@ -11,7 +11,7 @@ public external final class A {
 
     public companion object Companion {
         private constructor Companion()
-        @kotlin.js.nativeInvoke public final val foo: kotlin.Int = 0
+        @kotlin.js.nativeInvoke public final val foo: kotlin.Int
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         @kotlin.js.nativeInvoke public final fun foo(): kotlin.Unit
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.kt
index 057924be321..f5842bb1404 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.kt
@@ -4,34 +4,26 @@ external class A {
     class B {
         class C {
             @nativeInvoke
-            fun foo() {}
+            fun foo() { noImpl }
 
             @nativeInvoke
-            fun invoke(a: String): Int = 0
+            fun invoke(a: String): Int = noImpl
         }
 
         object obj {
             @nativeInvoke
-            fun foo() {}
+            fun foo() { noImpl }
 
             @nativeInvoke
-            fun invoke(a: String): Int = 0
+            fun invoke(a: String): Int = noImpl
         }
 
         companion object {
             @nativeInvoke
-            fun foo() {}
+            fun foo() { noImpl }
 
             @nativeInvoke
-            fun invoke(a: String): Int = 0
-        }
-
-        val anonymous = object {
-            @nativeInvoke
-            fun foo() {}
-
-            @nativeInvoke
-            fun invoke(a: String): Int = 0
+            fun invoke(a: String): Int = noImpl
         }
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.txt
index b665846638f..85bc40c3c14 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeInvoke/onNestedDeclarationsInsideNativeClass.txt
@@ -8,7 +8,6 @@ public external final class A {
 
     public final class B {
         public constructor B()
-        public final val anonymous: kotlin.Any
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.kt
index 42aca651511..b6d4ef55fc3 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.kt
@@ -2,48 +2,48 @@
 
 external class A {
     @nativeSetter
-    fun set(a: String, v: Any?): Any? = null
+    fun set(a: String, v: Any?): Any? = noImpl
 
     @nativeSetter
-    fun put(a: Number, v: String) {}
+    fun put(a: Number, v: String) { noImpl }
 
     @nativeSetter
-    fun foo(a: Int, v: String) {}
+    fun foo(a: Int, v: String) { noImpl }
 
     @nativeSetter
-    fun set4(a: Double, v: String): Any = 1
+    fun set4(a: Double, v: String): Any = noImpl
 
     @nativeSetter
-    fun set5(a: Double, v: String): CharSequence = "OK"
+    fun set5(a: Double, v: String): CharSequence = noImpl
 
     companion object {
         @nativeSetter
-        fun set(a: String, v: Any?): Any? = null
+        fun set(a: String, v: Any?): Any? = noImpl
 
         @nativeSetter
-        fun put(a: Number, v: String) {}
+        fun put(a: Number, v: String) { noImpl }
 
         @nativeSetter
-        fun foo(a: Int, v: String) {}
+        fun foo(a: Int, v: String) { noImpl }
 
         @nativeSetter
-        fun set4(a: Double, v: String): Any = 1
+        fun set4(a: Double, v: String): Any = noImpl
 
         @nativeSetter
-        fun set5(a: Double, v: String): CharSequence = "OK"
+        fun set5(a: Double, v: String): CharSequence = noImpl
     }
 }
 
 external class B {
     <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
-    val foo = 0
+    val foo: Int = noImpl
 
     <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
     object Obj1 {}
 
     companion object {
         <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
-        val foo = 0
+        val foo: Int = noImpl
 
         <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
         object Obj2 {}
@@ -52,20 +52,20 @@ external class B {
 
 external class C {
     @nativeSetter
-    fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
+    fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = noImpl
 
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-    fun set(): Any?<!> = null
+    fun set(): Any?<!> = noImpl
 
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-    fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = null
+    fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = noImpl
 
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-    fun set(a: String, v: Any, v2: Any)<!> {}
+    fun set(a: String, v: Any, v2: Any)<!> { noImpl }
 
     @nativeSetter
-    fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) {}
+    fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) { noImpl }
 
     @nativeSetter
-    fun foo(a: Number, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = "aa"<!>) = "OK"
+    fun foo(a: Number, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = noImpl<!>): String = noImpl
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.txt
index 02255dee7c8..8afc5f011d8 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.txt
@@ -26,14 +26,14 @@ public external final class A {
 
 public external final class B {
     public constructor B()
-    @kotlin.js.nativeSetter public final val foo: kotlin.Int = 0
+    @kotlin.js.nativeSetter public final val foo: kotlin.Int
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
     public companion object Companion {
         private constructor Companion()
-        @kotlin.js.nativeSetter public final val foo: kotlin.Int = 0
+        @kotlin.js.nativeSetter public final val foo: kotlin.Int
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.kt
index 46c944bd52b..bc4f69a6500 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.kt
@@ -4,48 +4,48 @@ external class A {
     class B {
         class A {
             @nativeSetter
-            fun set(a: String, v: Any?): Any? = null
+            fun set(a: String, v: Any?): Any? = noImpl
 
             @nativeSetter
-            fun put(a: Number, v: String) {}
+            fun put(a: Number, v: String) { noImpl }
 
             @nativeSetter
-            fun foo(a: Int, v: String) {}
+            fun foo(a: Int, v: String) { noImpl }
 
             @nativeSetter
-            fun set4(a: Double, v: String): Any = 1
+            fun set4(a: Double, v: String): Any = noImpl
 
             @nativeSetter
-            fun set5(a: Double, v: String): CharSequence = "OK"
+            fun set5(a: Double, v: String): CharSequence = noImpl
 
             companion object {
                 @nativeSetter
-                fun set(a: String, v: Any?): Any? = null
+                fun set(a: String, v: Any?): Any? = noImpl
 
                 @nativeSetter
-                fun put(a: Number, v: String) {}
+                fun put(a: Number, v: String) { noImpl }
 
                 @nativeSetter
-                fun foo(a: Int, v: String) {}
+                fun foo(a: Int, v: String) { noImpl }
 
                 @nativeSetter
-                fun set4(a: Double, v: String): Any = 1
+                fun set4(a: Double, v: String): Any = noImpl
 
                 @nativeSetter
-                fun set5(a: Double, v: String): CharSequence = "OK"
+                fun set5(a: Double, v: String): CharSequence = noImpl
             }
         }
 
         class B {
             <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
-            val foo = 0
+            val foo: Int = noImpl
 
             <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
             object Obj1 {}
 
             companion object {
                 <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
-                val foo = 0
+                val foo: Int = noImpl
 
                 <!WRONG_ANNOTATION_TARGET!>@nativeSetter<!>
                 object Obj2 {}
@@ -54,56 +54,39 @@ external class A {
 
         class C {
             @nativeSetter
-            fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
+            fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = noImpl
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(): Any?<!> = null
+            fun set(): Any?<!> = noImpl
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = null
+            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = noImpl
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(a: String, v: Any, v2: Any)<!> {}
+            fun set(a: String, v: Any, v2: Any)<!> { noImpl }
 
             @nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) {}
+            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) { noImpl }
 
             @nativeSetter
-            fun foo(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Double = 0.0<!>, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = "str"<!>) = "OK"
+            fun foo(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Double = noImpl<!>, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = noImpl<!>): String = noImpl
         }
 
         object obj {
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(): Any?<!> = null
+            fun set(): Any?<!> = noImpl
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = null
+            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = noImpl
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(a: String, v: Any, v2: Any)<!> {}
+            fun set(a: String, v: Any, v2: Any)<!> { noImpl }
 
             @nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) {}
+            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) { noImpl }
 
             @nativeSetter
-            fun foo(a: Int, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = "str"<!>) = "OK"
-        }
-
-        val anonymous = object {
-            <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(): Any?<!> = null
-
-            <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>): Any?<!> = null
-
-            <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>@nativeSetter
-            fun set(a: String, v: Any, v2: Any)<!> {}
-
-            @nativeSetter
-            fun set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: A<!>, v: Any?) {}
-
-            @nativeSetter
-            fun foo(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Number = 0.0<!>, v: String) = "OK"
+            fun foo(a: Int, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = noImpl<!>): String = noImpl
         }
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.txt
index 939702c6e39..e8a308fa324 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.txt
@@ -8,7 +8,6 @@ public external final class A {
 
     public final class B {
         public constructor B()
-        public final val anonymous: kotlin.Any
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
@@ -39,14 +38,14 @@ public external final class A {
 
         public final class B {
             public constructor B()
-            @kotlin.js.nativeSetter public final val foo: kotlin.Int = 0
+            @kotlin.js.nativeSetter public final val foo: kotlin.Int
             public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             public companion object Companion {
                 private constructor Companion()
-                @kotlin.js.nativeSetter public final val foo: kotlin.Int = 0
+                @kotlin.js.nativeSetter public final val foo: kotlin.Int
                 public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.kt
index 7bf2a09e1ca..6b45f74d50b 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.kt
@@ -24,11 +24,11 @@ external class TopLevelNative {
 
     class B
 
-    fun foo() = 23
+    fun foo(): Int = noImpl
 
     <!NESTED_EXTERNAL_DECLARATION!>external fun bar(): Int<!>
 
-    val x = "a"
+    val x: String = noImpl
 
     <!NESTED_EXTERNAL_DECLARATION!>external val y: String<!>
 }
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.txt
index 73dc68c4d06..bdd86daba13 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/nested.txt
@@ -38,7 +38,7 @@ public final class TopLevel {
 
 public external final class TopLevelNative {
     public constructor TopLevelNative()
-    public final val x: kotlin.String = "a"
+    public final val x: kotlin.String
     public external final val y: kotlin.String
     public final external fun bar(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/native.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/native.kt
index 40ac0dc5868..41442764118 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/native.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/native.kt
@@ -5,7 +5,7 @@ external val baz: Int
 external val boo: Int = noImpl
 
 external fun foo()
-external fun bar() {}
+external fun bar() { noImpl }
 
 external interface T {
     val baz: Int
@@ -27,7 +27,7 @@ external class C {
     val boo: Int = noImpl
 
     fun foo()
-    fun bar() {}
+    fun bar() { noImpl }
 
     companion object {
         val baz: Int
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeInvoke.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeInvoke.kt
index 53784154f42..34cbfc0574c 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeInvoke.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeInvoke.kt
@@ -9,5 +9,5 @@ external object O {
     @nativeInvoke
     fun foo()
     @nativeInvoke
-    fun bar() {}
+    fun bar() { noImpl }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/overrideOptionalParam.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/overrideOptionalParam.kt
index 9a8ccb00f13..1bdb2180a1b 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/overrideOptionalParam.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/overrideOptionalParam.kt
@@ -7,7 +7,7 @@ class B : A() {
 }
 
 external class C : A() {
-    override fun f(x: Int) {}
+    override fun f(x: Int)
 }
 
 
@@ -24,7 +24,7 @@ open external class D {
 }
 
 class E : D() {
-    override fun f(x: Int) {}
+    override fun f(x: Int) { }
 }
 
 class F : D(), I {
@@ -32,7 +32,7 @@ class F : D(), I {
 }
 
 external class G : D(), I {
-    override fun f(x: Int) {}
+    override fun f(x: Int)
 }
 
 open class X {
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/native.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/native.kt
index c9dcb24ff9f..3da0bdaf335 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/native.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/native.kt
@@ -1,12 +1,12 @@
 external fun foo(a: String): Int = noImpl
 
 external class Bar(b: Int, c: Char) {
-    fun baz(d: Int) {}
+    fun baz(d: Int) { noImpl }
 }
 
 external object Obj {
-    fun test1(e: String) {}
+    fun test1(e: String) { noImpl  }
     object Nested {
-        fun test2(g: Int) {}
+        fun test2(g: Int) { noImpl }
     }
 }
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeInvoke.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeInvoke.kt
index 07e52928695..39789ab212f 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeInvoke.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeInvoke.kt
@@ -4,15 +4,15 @@ fun Int.foo(a: String): Int = noImpl
 
 external class Bar(b: Int, c: Char) {
     @nativeInvoke
-    fun baz(d: Int) {}
+    fun baz(d: Int) { noImpl }
 }
 
 external object Obj {
     @nativeInvoke
-    fun test1(e: String) {}
+    fun test1(e: String) { noImpl }
 
     object Nested {
         @nativeInvoke
-        fun test2(g: Int) {}
+        fun test2(g: Int) { noImpl }
     }
 }
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeSetter.kt b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeSetter.kt
index ed41b75210d..2316550723e 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeSetter.kt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/unusedParam/nativeSetter.kt
@@ -4,15 +4,15 @@ fun Int.foo(a: String, v: Int): Int = noImpl
 
 external class Bar(b: Int, c: Char) {
     @nativeSetter
-    fun baz(d: Int, v: Int) {}
+    fun baz(d: Int, v: Int) { noImpl }
 }
 
 external object Obj {
     @nativeSetter
-    fun test1(e: String, v: Any) {}
+    fun test1(e: String, v: Any) { noImpl }
 
     object Nested {
         @nativeSetter
-        fun test2(g: Int, v: Any) {}
+        fun test2(g: Int, v: Any) { noImpl }
     }
 }
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java
index f4bdcb8f558..d22c9ee826a 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java
@@ -569,6 +569,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithJsStdLib/native"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("body.kt")
+        public void testBody() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/native/body.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("extensionFunctionAndProperty.kt")
         public void testExtensionFunctionAndProperty() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/native/extensionFunctionAndProperty.kt");
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt
index 3e6df6c18ce..dc094112395 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt
@@ -75,6 +75,7 @@ private val DIAGNOSTIC_FACTORY_TO_RENDERER by lazy {
         put(ErrorsJs.INLINE_EXTERNAL_DECLARATION, "Inline external declaration")
         put(ErrorsJs.NON_ABSTRACT_MEMBER_OF_EXTERNAL_INTERFACE,
             "Only nullable properties of external interfaces are allowed to be non-abstract")
+        put(ErrorsJs.WRONG_BODY_OF_EXTERNAL_DECLARATION, "Wrong body of external declaration. Must be either ' = noImpl' or { noImpl }")
 
         this
     }
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java
index 57c60ceb739..5f395b01e4c 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java
@@ -78,8 +78,9 @@ public interface ErrorsJs {
             ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory0<KtDeclaration> INLINE_EXTERNAL_DECLARATION = DiagnosticFactory0.create(
             ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
-    DiagnosticFactory0<KtDeclaration> NON_ABSTRACT_MEMBER_OF_EXTERNAL_INTERFACE = DiagnosticFactory0.create(
+    DiagnosticFactory0<KtExpression> NON_ABSTRACT_MEMBER_OF_EXTERNAL_INTERFACE = DiagnosticFactory0.create(
             ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
+    DiagnosticFactory0<KtExpression> WRONG_BODY_OF_EXTERNAL_DECLARATION = DiagnosticFactory0.create(ERROR);
 
     @SuppressWarnings("UnusedDeclaration")
     Object _initializer = new Object() {
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsExternalChecker.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsExternalChecker.kt
index be898e0eaab..6e9f0a407fe 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsExternalChecker.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsExternalChecker.kt
@@ -22,18 +22,22 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.js.PredefinedAnnotation
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.KtDeclaration
-import org.jetbrains.kotlin.psi.KtProperty
+import org.jetbrains.kotlin.name.FqNameUnsafe
+import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.checkers.SimpleDeclarationChecker
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassNotAny
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperInterfaces
 import org.jetbrains.kotlin.resolve.descriptorUtil.isExtension
+import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.utils.singletonOrEmptyList
 
 object JsExternalChecker : SimpleDeclarationChecker {
+    val NO_IMPL_PROPERTY_NAME = FqNameUnsafe("kotlin.js.noImpl")
+
     override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink,
                        bindingContext: BindingContext) {
         if (!AnnotationsUtils.isNativeObject(descriptor)) return
@@ -85,6 +89,34 @@ object JsExternalChecker : SimpleDeclarationChecker {
         ) {
             diagnosticHolder.report(ErrorsJs.NON_ABSTRACT_MEMBER_OF_EXTERNAL_INTERFACE.on(declaration))
         }
+
+        checkBody(declaration, diagnosticHolder, bindingContext)
+    }
+
+    private fun checkBody(declaration: KtDeclaration, diagnosticHolder: DiagnosticSink, bindingContext: BindingContext) {
+        if (declaration is KtDeclarationWithBody && !declaration.hasValidExternalBody(bindingContext)) {
+            reportWrongBody(declaration.bodyExpression!!, diagnosticHolder, bindingContext)
+        }
+        else if (declaration is KtDeclarationWithInitializer && declaration.initializer?.isNoImplExpression(bindingContext) == false) {
+            reportWrongBody(declaration.initializer!!, diagnosticHolder, bindingContext)
+        }
+        if (declaration is KtCallableDeclaration) {
+            for (defaultValue in declaration.valueParameters.mapNotNull { it.defaultValue }) {
+                checkExternalExpression(defaultValue, diagnosticHolder, bindingContext)
+            }
+        }
+    }
+
+    private fun checkExternalExpression(expression: KtExpression, diagnosticHolder: DiagnosticSink, bindingContext: BindingContext) {
+        if (!expression.isNoImplExpression(bindingContext)) {
+            reportWrongBody(expression, diagnosticHolder, bindingContext)
+        }
+    }
+
+    private fun reportWrongBody(expression: KtExpression, diagnosticHolder: DiagnosticSink, bindingContext: BindingContext) {
+        if (bindingContext.diagnostics.forElement(expression).none { it.factory == ErrorsJs.WRONG_BODY_OF_EXTERNAL_DECLARATION }) {
+            diagnosticHolder.report(ErrorsJs.WRONG_BODY_OF_EXTERNAL_DECLARATION.on(expression))
+        }
     }
 
     private fun isDirectlyExternal(declaration: KtDeclaration, descriptor: DeclarationDescriptor): Boolean {