diff --git a/js/js.tests/test/org/jetbrains/k2js/test/semantics/ClassInheritanceTest.java b/js/js.tests/test/org/jetbrains/k2js/test/semantics/ClassInheritanceTest.java
index f5001ca9c92..644778294c3 100644
--- a/js/js.tests/test/org/jetbrains/k2js/test/semantics/ClassInheritanceTest.java
+++ b/js/js.tests/test/org/jetbrains/k2js/test/semantics/ClassInheritanceTest.java
@@ -55,6 +55,10 @@ public final class ClassInheritanceTest extends SingleFileTranslationTest {
     public void testAbstractVarOverride() throws Exception {
         fooBoxTest();
     }
+
+    public void testKt3499() throws Exception {
+        fooBoxTest();
+    }
 }
 
 
diff --git a/js/js.translator/src/org/jetbrains/k2js/translate/declaration/ClassDeclarationTranslator.java b/js/js.translator/src/org/jetbrains/k2js/translate/declaration/ClassDeclarationTranslator.java
index 03fb98ebfb1..bd58a268a8a 100644
--- a/js/js.translator/src/org/jetbrains/k2js/translate/declaration/ClassDeclarationTranslator.java
+++ b/js/js.translator/src/org/jetbrains/k2js/translate/declaration/ClassDeclarationTranslator.java
@@ -129,7 +129,7 @@ public final class ClassDeclarationTranslator extends AbstractTranslator {
                     @NotNull
                     @Override
                     public Iterable<FinalListItem> getNeighbors(FinalListItem current) {
-                        TLinkedList<FinalListItem> parents = new TLinkedList<FinalListItem>();
+                        LinkedList<FinalListItem> parents = new LinkedList<FinalListItem>();
                         ClassDescriptor classDescriptor = getClassDescriptor(context().bindingContext(), current.declaration);
                         Collection<JetType> superTypes = classDescriptor.getTypeConstructor().getSupertypes();
 
@@ -147,6 +147,8 @@ public final class ClassDeclarationTranslator extends AbstractTranslator {
                     }
                 });
 
+        assert sortedOpenClasses.size() == openList.size();
+
         // second pass: generate
         Iterator<FinalListItem> it = sortedOpenClasses.descendingIterator();
         while (it.hasNext()) {
diff --git a/js/js.translator/testFiles/inheritance/cases/kt3499.kt b/js/js.translator/testFiles/inheritance/cases/kt3499.kt
new file mode 100644
index 00000000000..2fd7f4a19a0
--- /dev/null
+++ b/js/js.translator/testFiles/inheritance/cases/kt3499.kt
@@ -0,0 +1,13 @@
+package foo
+
+trait A : B, E
+trait B
+open class C {
+  fun foo() = true
+}
+trait D
+trait E
+trait F : G, D
+trait G
+
+fun box() = C().foo()
\ No newline at end of file