diff --git a/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegatePropertyTest.java b/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegatePropertyTest.java
index e0b713cf01e..63c7b7bba0a 100644
--- a/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegatePropertyTest.java
+++ b/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegatePropertyTest.java
@@ -47,7 +47,7 @@ public class DelegatePropertyTest extends SingleFileTranslationTest {
         checkFooBoxIsOk();
     }
 
-    public void testDelegateForExtProperty() throws Exception {
+    public void testDelegateByExtensionProperty() throws Exception {
         checkFooBoxIsOk();
     }
 
diff --git a/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegationTest.java b/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegationTest.java
index 4b40d9af614..622c0b76326 100644
--- a/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegationTest.java
+++ b/js/js.tests/test/org/jetbrains/k2js/test/semantics/DelegationTest.java
@@ -91,4 +91,8 @@ public class DelegationTest extends SingleFileTranslationTest {
     public void testDelegationExtProp() throws Exception {
         checkFooBoxIsOk();
     }
+
+    public void testDelegationExtensionPropertyDelegated() throws Exception {
+        checkFooBoxIsOk();
+    }
 }
diff --git a/js/js.translator/testData/delegateProperty/cases/delegateByExtensionProperty.kt b/js/js.translator/testData/delegateProperty/cases/delegateByExtensionProperty.kt
new file mode 100644
index 00000000000..e50af058cee
--- /dev/null
+++ b/js/js.translator/testData/delegateProperty/cases/delegateByExtensionProperty.kt
@@ -0,0 +1,39 @@
+package foo
+
+class State(var realValue: Int)
+
+fun format(event: String, property: String, value: Int): String
+    = "${event}: ${property} = ${value}; "
+
+object LoggerDelegate {
+    var log = ""
+
+    fun get(state: State, desc: PropertyMetadataImpl): Int {
+        log += format("get", desc.name, state.realValue)
+        return state.realValue
+    }
+
+    fun set(state: State, desc: PropertyMetadataImpl, value: Int) {
+        log += format("set", desc.name, value)
+        state.realValue = value
+    }
+}
+
+var State.value by LoggerDelegate
+
+fun box(): String {
+    val state = State(1)
+    var expectedLog = ""
+
+    assertEquals(1, state.value)
+    expectedLog += format("get", "value", 1)
+
+    state.value = 3
+    expectedLog += format("set", "value", 3)
+
+    assertEquals(3, state.value)
+    expectedLog += format("get", "value", 3)
+
+    assertEquals(expectedLog, LoggerDelegate.log)
+    return "OK"
+}
\ No newline at end of file
diff --git a/js/js.translator/testData/delegateProperty/cases/delegateForExtProperty.kt b/js/js.translator/testData/delegateProperty/cases/delegateForExtProperty.kt
deleted file mode 100644
index 1a79bc00d9d..00000000000
--- a/js/js.translator/testData/delegateProperty/cases/delegateForExtProperty.kt
+++ /dev/null
@@ -1,14 +0,0 @@
-package foo
-
-class Delegate {
-    fun get(t: A, p: PropertyMetadata): Int = 1
-}
-
-val A.prop: Int by Delegate()
-
-class A {
-}
-
-fun box(): String {
-    return if (A().prop == 1) "OK" else "fail"
-}
diff --git a/js/js.translator/testData/delegation/cases/delegationExtensionPropertyDelegated.kt b/js/js.translator/testData/delegation/cases/delegationExtensionPropertyDelegated.kt
new file mode 100644
index 00000000000..a9db7607012
--- /dev/null
+++ b/js/js.translator/testData/delegation/cases/delegationExtensionPropertyDelegated.kt
@@ -0,0 +1,40 @@
+package foo
+
+class State(var value: Int)
+
+trait Base {
+    var State.multiplied: Int
+}
+
+class Delegate(val multiplier: Int) {
+    fun get(state: State, desc: PropertyMetadataImpl): Int  = multiplier * state.value
+
+    fun set(state: State, desc: PropertyMetadataImpl, value: Int) {
+        state.value = value / multiplier
+    }
+
+}
+
+open class BaseImpl() : Base {
+    override var State.multiplied: Int by Delegate(2)
+}
+
+class Derived() : Base by BaseImpl() {
+    fun getValueMultiplied(state: State): Int = state.multiplied
+
+    fun setValueMultiplied(state: State, value: Int) {
+        state.multiplied = value
+    }
+}
+
+fun box(): String {
+    val d = Derived()
+
+    val state = State(2)
+    assertEquals(4, d.getValueMultiplied(state))
+
+    d.setValueMultiplied(state, 10)
+    assertEquals(10, d.getValueMultiplied(state))
+
+    return "OK"
+}
\ No newline at end of file