diff --git a/teavm-classlib/src/main/java/org/teavm/classlib/java/util/TTreeSet.java b/teavm-classlib/src/main/java/org/teavm/classlib/java/util/TTreeSet.java
new file mode 100644
index 000000000..5d8ef7815
--- /dev/null
+++ b/teavm-classlib/src/main/java/org/teavm/classlib/java/util/TTreeSet.java
@@ -0,0 +1,144 @@
+package org.teavm.classlib.java.util;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class TTreeSet<E> extends TAbstractSet<E> implements TNavigableSet<E> {
+    private static final Object VALUE = new Object();
+    private TTreeMap<E, Object> map;
+
+    public TTreeSet() {
+        map = new TTreeMap<>();
+    }
+
+    public TTreeSet(TComparator<? super E> comparator) {
+        map = new TTreeMap<>(comparator);
+    }
+
+    public TTreeSet(TCollection<? extends E> coll) {
+        map = new TTreeMap<>();
+        for (TIterator<? extends E> iter = coll.iterator(); iter.hasNext();) {
+            map.put(iter.next(), VALUE);
+        }
+    }
+
+    public TTreeSet(TSortedSet<E> s) {
+        map = new TTreeMap<>(s.comparator());
+        for (TIterator<? extends E> iter = s.iterator(); iter.hasNext();) {
+            map.put(iter.next(), VALUE);
+        }
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public TIterator<E> iterator() {
+        return map.keySet().iterator();
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+    @Override
+    public boolean add(E e) {
+        return map.put(e, e) != VALUE;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return map.remove(o) == VALUE;
+    }
+
+    @Override
+    public TComparator<? super E> comparator() {
+        return map.comparator();
+    }
+
+    @Override
+    public TSortedSet<E> subSet(E fromElement, E toElement) {
+        return map.subMap(fromElement, true, toElement, false).navigableKeySet();
+    }
+
+    @Override
+    public TSortedSet<E> headSet(E toElement) {
+        return map.headMap(toElement, false).navigableKeySet();
+    }
+
+    @Override
+    public TSortedSet<E> tailSet(E fromElement) {
+        return map.tailMap(fromElement, true).navigableKeySet();
+    }
+
+    @Override
+    public E first() {
+        return map.firstKey();
+    }
+
+    @Override
+    public E last() {
+        return map.lastKey();
+    }
+
+    @Override
+    public E lower(E e) {
+        return map.lowerKey(e);
+    }
+
+    @Override
+    public E floor(E e) {
+        return map.floorKey(e);
+    }
+
+    @Override
+    public E ceiling(E e) {
+        return map.ceilingKey(e);
+    }
+
+    @Override
+    public E higher(E e) {
+        return map.higherKey(e);
+    }
+
+    @Override
+    public E pollFirst() {
+        TMap.Entry<E, Object> entry = map.pollFirstEntry();
+        return entry != null ? entry.getKey() : null;
+    }
+
+    @Override
+    public E pollLast() {
+        TMap.Entry<E, Object> entry = map.pollLastEntry();
+        return entry != null ? entry.getKey() : null;
+    }
+
+    @Override
+    public TNavigableSet<E> descendingSet() {
+        return map.descendingKeySet();
+    }
+
+    @Override
+    public TIterator<E> descendingIterator() {
+        return map.descendingKeySet().iterator();
+    }
+
+    @Override
+    public TNavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+        return map.subMap(fromElement, true, toElement, false).navigableKeySet();
+    }
+
+    @Override
+    public TNavigableSet<E> headSet(E toElement, boolean inclusive) {
+        return map.headMap(toElement, inclusive).navigableKeySet();
+    }
+
+    @Override
+    public TNavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+        return map.tailMap(fromElement, inclusive).navigableKeySet();
+    }
+}