diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TTreeMap.java b/classlib/src/main/java/org/teavm/classlib/java/util/TTreeMap.java
index 9b2493631..e5a703459 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TTreeMap.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TTreeMap.java
@@ -16,6 +16,7 @@
 package org.teavm.classlib.java.util;
 
 import org.teavm.classlib.java.io.TSerializable;
+import org.teavm.classlib.java.lang.TCloneNotSupportedException;
 import org.teavm.classlib.java.lang.TCloneable;
 
 public class TTreeMap<K, V> extends TAbstractMap<K, V> implements TCloneable, TSerializable, TNavigableMap<K, V> {
@@ -558,10 +559,19 @@ public class TTreeMap<K, V> extends TAbstractMap<K, V> implements TCloneable, TS
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public Object clone() {
-        TTreeMap<?, ?> copy = (TTreeMap<?, ?>) super.clone();
-        copy.cachedEntrySet = null;
-        return copy;
+        try {
+            TTreeMap<K, V> map = (TTreeMap<K, V>) super.clone();
+            map.root = null;
+            map.modCount = 0;
+            map.cachedEntrySet = null;
+            map.putAll(this);
+
+            return map;
+        } catch (TCloneNotSupportedException e) {
+            return null;
+        }
     }
 
     static class EntrySet<K, V> extends TAbstractSet<Entry<K, V>> implements TSequencedSet<Entry<K, V>> {
diff --git a/tests/src/test/java/org/teavm/classlib/java/util/TreeMapTest.java b/tests/src/test/java/org/teavm/classlib/java/util/TreeMapTest.java
index 06e05e08a..f17dd85e2 100644
--- a/tests/src/test/java/org/teavm/classlib/java/util/TreeMapTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/util/TreeMapTest.java
@@ -215,6 +215,10 @@ public class TreeMapTest {
         Set<Object> key2 = map2.keySet();
         assertTrue("keySet() is identical", key2 != keys);
         assertEquals("keySet() was not cloned", "key2", key2.iterator().next());
+        @SuppressWarnings("unchecked")
+        Map<Object, Object> map3 = (Map<Object, Object>) map.clone();
+        map3.put("key2", "value2");
+        assertFalse("Original map modified through clone", map.containsKey("key2"));
     }
 
     @Test